There's some very sensible responses here (I suspect we're all getting older

).
I'm going backwards and forwards between the options, as I know I don't
need one, but I
love tech. There's a few factors that are making this a hard choice for me, lack of time, family sharing, quick-resume, low budget (currently) - I'll try to cover them briefly as the first time I tried turned this into a long post..
I have a PS4 Slim, with VR, 2 Controllers, PS Move Controllers, 2TB HDD, Thrustmaster T150, Current PS+ and EA subscriptions (which I probably won't resume). I like it, however games take a long time to load and I don't have much time to play, quick resume is great but the family also use it, so half the time a different game is 'saved' when I return to it. I also have a HTPC, but it needs TLC as it occasionally just doesn't want to POST until I reset the BIOS - I use this more than the PS4, however.
PS5 Considerations:
Pros:
Potential single console under the TV.
My steering wheel will work with it.
PS VR is compatible
It'll last x years for the 'new' generation.
Gran Turismo?
Unsure:
I'm concerned about fan noise, Sony have a bad track record with the PS4.
PS VR is compatible, but not sure it'll benefit on the PS5.
Not sure if I'll need another camera for PS VR.
Backwards compatibility is an unknown.
I enjoy playing GT Sport with the guys on the forum, but I haven't done it much (I had the same problem with Driveclub) as I don't have enough time to learn the circuits/cars properly.
Cons:
The console looks horrendous (I know some people like it, I really really don't).
DS4 Controllers don't work cross-generation, I'll need to buy an extra one on top of the console.
I don't get much benefit from PS Plus, I only bought it for GT Sport online features, which I use rarely.
I tried PS Now, didn't get much out of it, games I did want to play left the platform too quickly for my liking.
EA Access/Play is very limited on Playstation.
Xbox Series X/S:
Pros:
Game Pass/Ultimate (currently using with my HTPC, discovered some gems), which I can share with Son 1 (PC Gamer) and Son 2 (Xbox Gamer).
EA Access/Play is included (also usable on PC!).
Cross-generation controller compatibility.
It'll be quiet, I'm confident of this.
Backwards compatibility is excellent.
Multi-game resume!
Xbox All Access, smaller monthly payment.
It'll last x years for the 'new' generation.
Cons:
My steering wheel won't work on it.
No VR, the PS4 would have to stay under the TV to placate the family.
OR, Upgrade the HTPC:
Pros:
More flexible, free games on Epic Games Store, able to run emulators (currently it's not powerful enough).
Game Pass (though I would feel more tempted to continue with this if I had an Xbox, strangely).
I can use it with my steering wheel (but have only ever done once, because it's not plug-n-play like the PS4).
Cons:
More expensive (VERY expensive if I want to match XboxSX/PS5 performance).
When I eventually upgrade my TV, HDR will be fiddly against the 'just works' of the consoles.
Games require tweaking to get consistent performance, I usually just choose something to give me 60fps-ish as I don't want to spend ages tweaking.
It can run emulators, as above, I'll spend ages tweaking them and probably never actually play the games.
I'm constantly on the hunt for components to upgrade it (I can't help myself, feel the need to remove the temptation).
When it stops working I need to fix it, which I don't have time / can't be bothered to do.
My youngest son is disappointed when it stops working and he wants to play.
It's still pretty long, and I realise the Pros/Cons are specific to me, but now I've written that out.. the choice seems obvious.