For example, Xbox SSD and PS5, due to their differences in speed and priority levels, the amount of data inside the ram of each console will also be different, at any given time. It may also affect the fidelity of the game. My guess is that Xbox games gonna have higher native res but with lower polygons and lower texture, PS5 with lower native res but higher polygons counts with high res textures. I doubt that 3rd party devs will make full use of that, they will prioritize the slowest denominator and call it a day. As always only Sony's studio gonna make full use of the hardware down to the metal.
Edit: i mean xbox will also have high res textures but load slower.