GT6 ---- > GT7 = Just a little bit over 8 years.
And the transition in hardware was massive. You are already reaching a point where going beyond a certain resolution and refresh rate doesn't bring any benefits unless you play on a big ass cinema screen or something, where even 4k will definitely not cut it.
But other than those very insignificant scenarios, 4k is already as good as it gets, and actually, even now, years after 4k has been "standart", people still see 1440p as a pretty good sweet spot, especially on something like 27inch monitor. For 55-65 inch TVs, 4k is really good as it is.
Even more irrelevant is refresh rate these days. Which for racing games, 60fps is exceptionally good as it is. Higher refresh rates than 60fps will only benefit open world 3rd/1st person view games, and mostly shooters.
I played CS:GO for a few years, and when I made the change from 60 to 144hz, I was astonished, it made a world of difference. However, after I tried out a 240hz, I barely saw any improvement, and there's videos on youtube with more casuals unable to tell the difference between 144hz and 240hz, but can easily tell the difference between 60 and 144...
I could see (barely, and this is because I'm someone who plays a lot) a bit more fluidity but barely anything worth mentioning. We already have 360hz monitors and from the reviews I'm seeing, unless you play at the pro level at something where every single .1% of an improvement matters, they are not worth buying.
It's been scientifically proven that the higher the refresh rates we get from now on (240hz and above) you get diminished returns, to the point of being insignificant.
So, since you are likely not going to get huge advancements in terms of hardware, aside from maybe Ray Tracing, Gran Turismo 7 will definitely stand the test of time for a lot longer than its predecessors. In fact, the game itself is beind held back by the console's hardware and not the other way around. So it's more the console devs that have to rush more for either an updated PS5 console model (PS5 Pro?) or a new console rather than the game devs rushing to make a new game to "keep up with the times".
You won't see Gran Turismo 8 anywhere before 2027/2028, which is going to be about the time the PS6 is likely to release.
Yearly titles (basically almost anything EA, Activision) for me have been a complete waste of money. I'm still astonished at how many people keep buying these games, when they should've realized by now that the games year in, year out, are the exact same with minimal added features/graphics and with just roster updates... that could've been updates by themselves in the first place and not full 70-80€ "new" games.
Gran Turismo 7 has a lot of flaws, but I would never trade it for something as rubbish as F1 games. And I'm an F1 fan myself who would like to have some more real life F1 cars in GT. I stopped playing F1 games since F1 2013. I then decided to go for F1 2020 to see if the franchise has improved or not, and I found it pretty damn mediocre.