Shameful: yes, this list is shameful for Canon, when you want to be the #1 on the market and charge prices of 4000+ euros for the cameras, while you're behind the competition regarding 20 important points. Historically Canon probably never has been that far behind in modern features, although they have just released their flagship products.
Who is their main competitor? Because I don't see 20 points where they are behind against Nikon
APS-C lenses: obviously this is an artificial limitation by Canon they could solve in a second if they like. If Canon full frame cameras had crop modes like Sony or Nikon, of course the use of such lenses would even be broader. With the new 4K crop that has no wide full frame alternative on the 5D4/1DX2, it would have been the right time to stop that stupid limitation!
it's not artificial. Put an EF-S lens on FF camera and the mirror hits the rear element. it is why they designed the EF-S mount the way they did.
What you are talking about is not EF-S lens compatabaility but sensor crop modes
Silent shooting: why not 100% silent? the 5D series are the wedding cameras #1, which photographer or guest enjoys the click noises? Canon simply needs to make a 5D4 mirrorless alternative. They could do, but for years first they try to figure out new camera systems with more different mounted lenses to the people and waste our lifetime.
The 6D is silent mode is very, very quiet. Why are you comparing it to 5D models when we are talking about a 6D v2? Have you even used the 6D?
Pixelshift: Pentax can do it, Canon probably does have a patent problem and want to protect their future high megapixel cameras, which is the main Canon philosophy: if you have 5 tasks, please buy and carry around 5 different cameras instead of 1. Just most people don't want or can do that, even if just a question of logistics and not money.
Nobody that I see has confirmed this is what the Pentax does.
Speedbooster: We can cross that off the list indeed, because unless all Canon full frame cameras don't have a crop shooting mode, it would be pretty useless anyway. And of course technically it's a problem aside from medium format lens adapter options.
The reason speedboosters were invented was to give shallower DOF because of the different characteristics of FF and MFT. A f4 image on MFT printed to the same size as a F picture has DOF of 5.6 on FF. So what you are saying is use APS-C crop mode then use a speed booster to produce a smaller image circle to give shallow DOF again. Why not just shoot at native f4 on FF and cut the expensive crap in the middle?
EVF: Nikon is even way more behind than Canon in many things, which is a problem because these two dinosaur companies havent realized yet it's not them alone anymore since it was decades, when they could slow down the pace as they liked. Unfortunately there is no pressure coming from Nikon, which makes it even more important to speak out as a Canon user.
But I thought Nikon was so far ahead of Canon in so many ways. I don't really see Sony as a competitor in the sense that 'Ooh, they have it so we must have it as well or lose market share'. Everything you mention is damn all to what really matters - image quality. Sony fall behind in one massive, important area - poor range of lenses. Canon gives an integrated system. Sony is not really the opposition to Canon, Nikon is and both companies believe that OVF with quality focus tracking and high quality post-sales support is the way to a successful company. Sony is said to have a great AF system - I dont recall seeing a single one.
If you want to see how Sony fares in traditional photographer working life:
https://www.dpreview.com/articles/5684109129/lucky-number-7-shooting-pro-sports-with-the-sony-a7r-ii
So how far ahead is Sony in what matters? A real world-beater, obviously.
Fully assignable buttons: Like in a Sony camera, simply allow any function on any button of the camera - not just 2-10 random features like in a Canon camera menu. This way the A7R2 already does have a third wheel for ISO if you like by the way.
Is that really a 'deficiency'? Will that really affect your buying decision?