Launch GT7 << GT5 and GT6
Current GT7 >> GT5 and GT6
Don't care about car quantity, otherwise GT3 would be the worst. And as stated, GT5 and GT6's car lists were mostly filled with filler cars. GT7 at least has all of them with the propper attention to detail they deserve.
GT7 was, and still is, the most disappointing Gran Turismo to date though. But objectively speaking, its better than GT5 and GT6.
All of this taking into consideration the time all of the games were released on. GT1 now is clearly a dated game, but for the time, it was a masterpiece and a revolution in racing games, the first of its kind. GT2 was a massive improvement over it though.
Same with GT3 and GT4 which worked out in the same way GT1 and GT2 did.
GT7 is still massively lacking on car varitation events. And the way they are laid out is for me the worst to date. Choosing to display the events at the TRACKS instead of the EVENTS themselves like even GT Sport did, was a terribly foolish decision. It's hard to not get a bit annoyed at this. And the game doesn't feel at all like it has a career... Just races all over the place, the License Tests don't even mean crap anymore for whatever reason.