Interesting. So you think the standard of played has improved over the last 20 years because of the input of computers in youngsters' development?
I agree to an extent but regardless of one's training, I think some players have more natural chess logic, I'd be really interested to see how Kasparov fared against Nakamura or Wesley - it's academic though, I don't think he'll ever return now. Perhaps this is best as it won't tarnish his legacy.
Regarding age, do you consider that a factor? Kasparov isn't that old, really - 52 this year. I've never really known if age affects one's ability or judgement in Chess. Karpov is still involved in occasional tournaments, although I've no idea at what level.
Yes. This is an interesting topic actually.
The thing is, the new players have far more experience and practice than the generations that didn't have computers at their disposal, simply because they can learn more, much quicker.
In Kasparov's days they would spend days analyzing a single position just trying to know if it's better for white or black, and then come up with a judgement about a single move. Now any player can just let the engine run for a couple of minutes and he'll immediately know if it's good or bad, and he can easily follow the computer lines to see why. So instead of spending 6 hours to study a single position, now any player can study over 20 positions in the same time with even more accurate final assessment. Big advantage for the new generation.
In fact, the openings theory have advanced (and changed) immensely after the emergence of computers. It made players look differently at many openings, and it helped expand the opening book a few folds.
Also, computers help the players find some crazy moves (and familiarize them with these type of moves) when in Kasparov's era those kind of moves will be completely overlooked by everybody, including Kasparov himself. New players are more likely to find those unusual moves that could potentially refute Kasparov's brilliant combinations, not because of their superior talent or creativity, but because they've seen these moves before.
Every generation in chess benefited from the previous generation because they learned a lot from them, and then added their touch. Players like Capablanca, Fischer, Kasparov, and even other players like Petrosian, Karpov, ...etc. all played an important role in the development of chess, because they made it easier for the next generation to learn from them. The new players didn't have to invent everything from scratch, but build on the previous generation and add to it, which is why chess kept developing, and the chess players became stronger and stronger with every new generation.
However, with the introduction of the "perfect chess player"/computers, the jump became much higher, because you're finally learning from a near perfect chess player, or more accurately, coach.
As for age, age is a big factor especially for players who rely on long calculations, which is one of Kasparov's main strengths, because you become more prone to mental lapses/blunders. Kasparov definitely started blundering more often in the 1990s, so at 52, it will be a big ask.
Also with age you start forgetting old preparations, openings, you just start forgetting a lot of stuff, and chess is even more about memory than creativity and calculations most of the time.