The SSD tech in consoles/pc should have been standard since 2013 generation, even though i understand that would have been costly. Ive had SSDs in my gaming pc since the x58/first i7 days, over eleven years ago. Due to costs this storage tech has been behind for much too long.
Very important hardware part, but the GPU, and then the CPU are most certainly the most important aspects still when it comes to just about anything gaming. In special considering GPUs are responsible for so much these days. Ram still plays a bigger role still too, i can imagine. It's where everything needs to go through, since ram leaps have stagnated alot (2x jump), nvme drives somewhat have to mitigate for that.
It's in my opinion that SSD tech (for Xbox, PC, PS5) is alot of overhyped, yes they are going to make a huge difference in loading times, quick resume/save states, and allow for smaller install sizes, probably also more assets. But they don't change games so significiantly as some claim.
The UE5 demo, one of the most impressive showcasings), apparently didn't require so much storage speeds.
DF even mentioned that the CPU is the biggest leap over the last generation of consoles, with a real cpu this time, i think devs can do much more intresting things with that then the SSD.
Also dont forget ray tracing, just about any next gen game has it, theres where the real changes in visuals seem to originate. It's the GPU thats the most important there.