Having just borrowed a PS4 to play Persona 5 Royal, I gotta say, I'd be down for a dramatic improvement in the UI department. The PS4's OS is so incredibly confusing and clunky (and occasionally very slow to get anything done), it's downright frustrating at times. Maybe I'm too spoiled with the Switch's snappy and straight-to-the-point OS, but I would hope that becomes the new base standard consoles should aim for.
It's acceptable for a home console interface to be a bit slower than something like the Switch, since it's a home console after all, but the PS4 falls quite a bit below what I'd consider acceptable. I mean, everytime I turn it back on from sleep mode, I'm automatically reset to the main user (spoiler: not mine) and have to manually change the user every single time even though I have the game open. (????) That's already bad enough, only made even worse by the fact that the change user option is in the POWER options tab... like, really?
There were also a few things I tried doing that took obscenely long... like, when I tried creating a new account, I had to wait for 5 minutes at some random "please wait" screen, before reading some contract bullshit, and at the end I still got an error that forced me to create my account with an alternate ID. And no, the internet connection wasn't bad, not even close.
I was considering getting either a PS5 or used PS4 in the mid-term future, now the PS4 option is mostly discarded. That said, I'm not sure I can expect much better things from the next one.