Earlier quoted context omitted.
I would like to differ on this. It's getting harder and harder to maintain dominance. Kasparov was the one to hold the longest. Magnus, even though he is one of the best ever, is already losing out to Alireza in bullet, blitz and even almost in classical. Chess theory has a new Renaissance due to neutral networks and we will see newer GM's adapting to it.
In fact, it was Magnus himself (currently 29 years old, as of April 2020) who said his favorite chess player was himself, when he was around 23. That Magnus apparently saw things on the board that current (overwhelmingly dominant) Magnus can't any more. So even in chess there's a physical prime, just like in pretty much any other sport.
Right now he's spending a lot of time promoting chess24 with banter blitz, hanging around on lichess playing 100 games bullet matches, commenting on chess24 and other things that would profoundly ruin anyone else's concentration.
So, no big deal if he very occasionally loses (online!) games.