We are reaching the point of diminishing returns on slight upgrades in power. We live in an age where Witcher 3, a game that was developed for consoles more powerful, is about to be available on Switch for portable play. Albeit in this case the difference is noticeable, the point is that it is no longer CAN the weaker console run the game. Unless the difference between Scarlet and PS5 is MASSIVE (it won't be), it will make little to no difference overall.
If someone wants Witcher portable, they will get it on Switch, pixels be damned. Likewise in the next gen, where specs will be alot closer anyway, if people want a game on gamepass or they got their Scarlet for Halo, they will buy the multiplat for that system. If they want their trophy info to continue from the PS4 or PS exclusives interest them more, they will get it on Playstation.
I mean having all 3 consoles myself, I can confirm that even playing Battlefield 4 had no noticeable difference compared to PS4 on the X1 when in motion. Only the people who were looking for fuel for the "console war" truly cared outside of a few tech enthusiasts that are just interested in the comparison.
Thats how I see it anyway.