Now that GPUs can reliably generate 60 FPS, this is the next step to push that technology. Because you'll need 45x60FPS for the same quality. And then you'll push the 45 number higher. (yes, I know the 60 isn't visible and has to do with control input).
https://developer.nvidia.com/vrworks/graphics/singlepassster...
In my mind you can render $x pixels at 60fps. So the number of pixels for each distinct view is: $x / 45.
With raytracing you will almost get this for free.
For another, the worst case cost is $x/45, but I would think that might improve as 3D programmers figure out optimizations in terms of multi angle view rendering.
That depends entirely on what you're rendering. You could reliably hit over 60 FPS for decades—for some content. And now you can still render at .000000001 FPS for other content.
Saying "GPUs can generate 60 FPS" is presenting the situation as if framerate were a function of hardware only, whereas the reality of the situation is that it depends at least as much on the software.
I remember this moment when Crytek released a real-time raytraced demo of one of their games running on the best hardware avaipat at the time. It felt like, finally the hardware is capable and now it's a slow march to the end of raster graphics. Then 4K displays came along and totally exploded the number of pixels to render and that was pretty much the end of that talk, at least for a couple decades.