I also didn't get it, and I guess you won't get it either unless you spend enough hours in GT7 VR with a PSVR2 + G Pro in a solid frame.
I was massively disappointed when I first tried GT7, rather stupidly I fell for the 4K hype and review videos and so was expecting 4K per eye. I thought about returning it but as it turns out that would have been a massive mistake. Once the G-Pro was dialled in for maximum realism and my brain had time enough to adjust to the new inputs generated by the VR and wheel, everything changed.
After 2 weeks I felt that I really missed the incredible 65" 4K HDR visuals of GT7 on my TV, so I moved the furniture (no mean feat) and dragged the Trophy back in front of the TV....
Wow... what a disappointment that was! After 10 minutes I switched it off and put everything back, vowing never to race outside of VR again. If you're watching someone else race then yes the 4K is great, but I do not miss it at all in VR because it is just so damn real. I know now that I will never, ever be tempted to go back to a flat screen.
Yes it's true that it is fiddly to get the sweet spot in PSVR2 and middle/far distance is a little 'fuzzy', but the sheer realism FAR outweighs this shortcoming and, after a while, it's hardly noticeable when you're racing. Near distance graphics, i.e. cars near to you and in-car graphics, still look amazing in VR, almost as good as 4K, and those are the only details that you really notice in the heat of a race.
With this kind of VR setup the ONLY thing missing is the G-force and your brain seems to forget all about that after a while, connecting all your other senses completely to the VR lie. Even after 2 months racing every day, every day it still blows my mind how real this feels and I exit the seat feeling like I just spent an hour in a real racing car. It's the TrueForce that makes all the difference, feeling every gear change, track detail and wheel scrub through the wheel and Trophy frame results in a truly real experience that I am now completely addicted to.
I actually spent the first 4 weeks in cars with a solid roof, then when I dropped into an open top car for the first time... BANG... VR delivered yet another huge WOW moment I won't soon forget. This just keeps on getting better and better. When I first raced F1 on my PS1 decades ago, I never imagined in my wildest dreams that this would be possible in the home within my lifetime.