Although I am buying both next gen machines (Ps5 at launch, the xbox scarlett a bit later) I am not expecting much at all. Because the difference will not be as big as it used to be. The jump will never be that big again, as it was from ps1 to ps2 and from ps2 to ps3.
Back then you could see at the first glance that the upcoming System is going to rock. But These days the differences are more subtle. And I do not care about these small differences in frame rate and Resolution at all.
I am just a console peasant

Still enjoying playing games on basic ps4 and the xbox one S on my 4K Screen and I cannot complain at all.
I think I will never be able to enjoy jumps in graphics at all. I have watched some footage of some games I know on youtube running with the latest pc graphics cards. And the difference was not overwhelming compared to my ps4 experience. It looks a bit better I guess but there was now effect.
So everything is up to the games . Tech will not be the reason why I get the next gen systems. The new games are the only reason why i want the next gen machines.