There is nothing better than GT series for the last 25 years on PS platform.
GT is more close to AC than to the ACC, but AC is rather old already, it has no proper PS5 support also the PS4 port is not very good and practically is even more broken for PS platform than ACC on PS5. I have them both for PS but don't play them because of this.
Note that, I also play AC and ACC but on PC very actively. I won't make comparison to the GT, they are just different and I enjoy them all in a different way.
This is a very interesting thread, and some excellent points have been made. I think this one sums it up rather nicely and is very close to my opinion.
Bottom line, they are different experiences, and IMHO, complementary. ACC focused more on the hare-core sim enthusiasts, and GT7 more general with its history as a game on a console, nostalgia, many cars, etc., but definitely much more "sim" than "arcade".
I started playing other racing titles like PCars and ACC when Polyphony left a void (GT6 was released in 2013 and underwhelming), and those games really took physics to another level. (Also dabbled a bit in iRacing which also has good physics and is definitely in the "pure sim" lane).
Since getting GT7 I haven't gone back to compare it to ACC, so I should probably do this for a better side-by-side view.
The #1 thing from ACC I wish GT7 would improve upon is AI - the way you can adjust it to your skill level is unparalleled in my experience in single player. It's clear from the "chili pepper" races, and now more so with Sophy, that Polyphony has the capability to make AI behave more like a real race and not do the "chase the rabbit" mode all the time. I think they are walking a fine line because the harder they make the AI the more of the overall average drivers they alienate, but I think ACC solves this well and PD should emulate that. GT7 looks like it could be almost ready to cross that chasm.
Either way, I think they are both excellent games with great strengths, and I would be very happy if ACC would release a version that is compatible with PS5 and supports PSVR2. I'm honestly not sure if they are actively developing anymore and if they would have the budget, inclination, and resources for this.