How will it be impossible to shoot wide angle? Two articles before this one is a patent for an RF 17-70, there's already a 15-35L, there is an RF-EF adapter to allow using the EF-S lenses, and there are already third party options coming out. There's far from zero options. The fact that current RF lens development is for full frame doesn't preclude it from use on an APS-C sensor camera as long as it has the RF mount.
On the other hand, I submit that, without an APS-C option, the RF mount - no matter how spectacular - is a dead-end proposition. Canon will never, and I do mean never, recoup the R&D investment into the R series camera and lenses by just selling cameras to enthusiasts. Compare sales of the Rebel line, for instance, to those of the 5D, and tell me which one is doing a better fiscal job of driving Canon's EF market. At some point, the RF mount is going to have to reach the mass market. And when that inevitably happens, there will be some who want the additional benefit of a crop sensor for telephoto shooting. I am one of those people. A camera is a tool, nothing more. And I would like the right tool for the job.
And right now, my only options are EF glass. The RF glass is pretty darned spectacular, but much like the EF-M lenses for my Canon M50, anything RF that I'd buy is a white elephant that can only be used on an RF mount camera. Which right now means only full frame. That's all fine and dandy, but let's consider that I decided to buy an EOS R or its ilk sometime soon (like I have been thinking about.) I have also been considering a telephoto lens, and have rented Canon's 100-400L II lens with spectacular results. I am enticed by the potential of the expected RF 70-400L. But why would I buy one when I couldn't use it with my APS-C camera? RIght now, buying an RF lens is intentionally limiting the usefulness of that lens. It's not an end of the world problem, but I am a LOT more likely to buy EF lenses that can be mounted on either my M50 or the R that I would buy. And that means that I would be , in effect, carrying elements of three different camera systems - EF-M, RF, and EF - rather than one. An APS-C sensor RF mount camera in my bag makes the decision to spend money on RF glass a lot easier to make.
Just my $0.02, cash value slightly lower.
Jody