To also give you a serious answer:
Probably yes. And a definitive yes, if we are talking mainstream offerings in the long term.
Did you actually try a R5 already? By all acounts that I am aware of, ergonomics of the R5 are comparable to the traditional 5 series and the EVF is an improvement over models used in previous Canon cameras in all aspects. Also, with regard to markings obscuring fine detail in the EVF, are you talking about focus peaking? That is an optional feature, you don't have to use it if you prefer to manually focus with a different aid. In this regard, an EVF should actually make life easier for you, as you have the option of seeing the true DoF (unlike on an OVF) and can zoom in even in the viewfinder for precise manual adjustments.
We have seen a number of advances in the R5 that would be hard to replicate in a 5 series DSLR, probalby impossible without increasing the price significantly:
- IBIS introduces challenges with regards to composition on an OVF camera (different framing on the sensor and the viewfinder) and can't be coordinated with EF lenses as well as RF ones due to the older, slower interface (both electronically and in terms of the communication)
- High FPS is associated with greater complexity on a DSLR, since in addition to the shutter, the mirror also has to move at these high speeds and the AF relying on the mirror is compromised. Even the 1DX III can't match the performance of its LiveView mode in OVF mode.
- Autofocus: The eye AF and greater tracking abilities appear to be impossible to implement in an OVF at a 5 series price point. Even with the 1DX III, where the AF sensor basically is a second image sensor (unlike in all previous Canon cameras), they can't even do eye AF.
Also, consider this: The R5 is not a cheap camera. As I just described, a potential 5D V would lack some of the R5's key features. If Canon released such a 5D camera, it would split the demand for a 5 series camera between these two, and therefore increase the price of both models.
With all this and the greater insight into the technical challenges aswell as the market itself Canon seems to have chosen to move the high end EF line towards the RF ecosystem. Even the 7D series, which is arguably the one benefitting the most from an OVF, hasn't seen an upgrade and is rumored to be canceled.
First of all, sorry for my slightly infantile style above, but it is my boomer dementia pressing in, in combination with a growing frustration over canon's poor choice in terms of viewfinders....;- )
IBIS, I don't care much for IS, I have it in my long lense and thát is very nice, but in my daily work, I don't have any use for it (< music, portraits and events, and a bit of amateur photography, whenever something is too pretty not to have its picture taken...;- )
Also, with IBIS, You get 8 stops of image stabilisation, but how often do You have an object that are sitting absolutely still for thát full second, that You can utilise with IBIS....???
IBIS is only useful for still-life images, whether thát is a handful of flowers on the table in low light, or a street-scene at night, or a landscape where one has stopped the lense down a very good deal (< on a absloutely wind-still day, well to note....;- )
-In its extremes, it is not useful for photo-jobs, and a low-light (f/2.0 and less) pro lense in combination with a highish ISO is generally a better solution than IS, as any movement will be stopped, and captured in a useable way.
Focus peaking, yea, that was what I meant, and if deselected, I will any day prefer to see the object's actual tones in the viewfinder, rather than a camera-generated jpg, I will much more know what I got thát way, and whether I can make an image of it.
Seriously, I will feel alienated in terms of looking into thát hole, detached from both the subject and my own creativity....
The high FPS of the R5, I don't care for it, and the few people who actually need it in their work, probably buy an 1D type camera....
DoF, I basically always shoot full open, so I got the DoF in my optical viewfinder, and should I need to stop down and get just the right DoF, then live-view is usually plenty.
-Any way, I will definitely prefer to have an optical viewfinder, with the advantages that thát one hold, and then use the live-view in the few situations where I need absolute control with a stopped down lense's DoF.
Eye AF, the only situation where I maybe could use eye AF is in live music photography, but, selecting a suitable focus-point and then keeping thát one on the mucisian's eye (or whatever I will want sharp), eventually while leaving a small bit of room around him/her, in order to be able to crop a small bit afterwards (which make a precision choice of focus-point slightly less necessary), is not terribly difficult to do.
-And so, plentifully efficient...
In my portraits I generally focus manually, in the way that I use AF to do the rough focusing, after which I focus by rocking back and forth a bit, that is by far the easiest and fastest and most efficient way of focusing in a portrait situation, with lenses such as 85L and 50L.
And in event-photography I generally just use autofocus in a normal manner, and despite using the mentioned lenses plus the 35L (which is also demanding in terms of focus), I very rarely miss a shot.
-In part because my camera have this incredible viewfinder, which make it super-easy to correct for a bit of movement manually (< much easier than refocusing/recomposing, and quite probably yielding better reults than what I would have if I left it to the camera's automatics, 5D or R5).
And if there's one thing that I hate more than anything, then it is to have to fiddle with the camera while interesting things are going on, and no, I can't see myself swiching back and forth between eye-focus and normal focus, or whatever....
As simple as possible, please, and again, thát does point towards the optical viewfinder, thát in combination with ISO, shutter speed and aperture set beforehand, and being able to shift between "One shot" and "Continous AF" by the button by Your ring-finger, and with the exposure control and focus points by Your thump, You got all the control that You need, in a standard "normal" 5D....
Really, the 1D and 5D cameras as they are, are masterpieces in terms of ergonomics, and it is completely and utterly stupid to change any of the basics....
Cheap, it should be quite cheap to port the R5 to a 5D5, and a lot of dissapointed canon customers will find a 5D5 very welcome, customers that canon absolutely are at risk of loosing, and thát is going to be expensive....
And video, despite having had the option since I bought my 5D2, I haven't really done much video, however, they did put a USB 3.2 in the 1Dx3, so an extern tablet-type monitor is becoming an option, and I will probably go there if I ever get a camera with such a connection.
But, and this is what I really want to get at here, no way that I will use AF for thát, You see ABSOLUTELY no professional filmmakers using autofocus, and really, who will want to do less than professional work....???
And then there is also downsides to the EVF kind of camera, like heated noisy sensors, and the less useful viewfinder mentioned earlier.
-Not to mention that they are ugly....;- )
"Canon seems to have chosen to move the high end EF line towards the RF ecosystem", and thát is quite possibly the single most stupid thing that they could have done, it would quite possible be pretty smart to give the crop-cameras an electronic viewfinder, as they basically haven't got an useable viewfinder anyway, but ABSOLUTELY not the pro/semipro fullframe cameras....
Back in the film-days, I never really thought of the viewfinder, it was just there, but man, when I bought my first digital camera, an Eos 400D cropcamera, whaaaat a shitty small hole thát was....
And despite buying the 85L at around the same point in time, I never grew as a photographer untill I got a fullframe camera, which depite its many, many advantages, more than anything gave me a viewfinder where I could actually see what I needed to see.
Now, these are my arguments, and really Joules (and sorry for the boomer style, but I did probably do serious photography before You were born....;- ), if You don't reckon/acknowledge the advantages of a highly enlarging 100% optical viewfinder, then we can't have a discussion, can we....?
-I'll seriously argue that more than pixels, ISO, dynamic range, ergonomics, screen and features, a really good optical viewfinder is what any skilled photographer need to be the best photographer that he can possibly be....
