I mean, ultimately, you're making an assumption about performance based on your assumption on price.Even PS6 probably wouldnt be able to do that lol.
A PS5 Pro could in theory be more expensive than a PS6.
Models change, just look at the iPhone. The original iPhone was $499 and by iPhone X it was $999.
I think we assume to much to think that the console market isn't going to change at all and that it will just quietly go away in lieu of the cloud and streaming.
I think you're going to see companies test the market and how much the market is willing to pay for consoles especially with GPUs costing 1000 plus in many cases.