An important piece of context here is that making a living by playing chess competitively is close to nil, so many even top players like Kramnik end up taking consulting/PR jobs like this in order to pay the bills. I have a hard time believing Kramnik actually believes (or said directly) that AI ruined chess. My read is that he's not really promoting changes to the rules of chess as much as he's trying to build support for new types of chess variants.
It's true that the highest levels of play include teams of researchers and computers that develop 30+ move preparation, but what we're also seeing as a result of that are games that are more precise, which IMO is a fundamental component of chess "beauty". Some notable games that were deemed "beautiful" in the past are now seen as less-beautiful as it became apparent that play was suboptimal. Chess beauty now is less about flashy combinations and more about qualities of a position and reverse engineering the "logic" behind certain AI moves, which is still great but admittedly requires more of an investment on learning the game than a spectator might care about.
That framing, though, leaves out the massive benefit that AI has had in training and improving new players. It used to be that you needed to hire a chess master to play against and learn from in order to improve. Now your phone can easily give you a challenge of master-level strength, as well as analyze your games over the board to look for improvements.