It will all depends on studios. The biggest benefit of PC gaming is that upgrading your hardware instantly unlocks higher frame rate and visual fidelity because higher resolution texture are already present in the code.I will wait and see what the PS5 Pro brings to the table, I might be pleasantly surprised. Digital Foundry wrote an analysis article based on leaked sources on the potential benefits to current games on the PS5 Pro. They surmise that upgrading from a PS5 to the Pro could be somewhat minimal in terms of game performance benefits.
This is not true for console gaming. Backwards compatibility rarely unlocks superior graphics unless the gaming studios have spent resources on updating a game.
Therefore the limiting factor isn't the hardware in the PS5 Pro but whether studios will optimise their game for it and to what extent versus designing for the lowest common denominator e.g PS5 and Series X. We won't have sight of this until 18-24 months after launch.