Transcript:
Elon: The actual number of moves that are not utterly stupid in chess is tiny and chess will be fully solved one day
Chess.com: Skill issue
Elon: Chess is hard for humans, but not for computers. One day, it will be fully solved like checkers. Between now and then, or even after, have fun. People enjoy may games/sports where machines are vastly better.
Chess.com: There are more possible chess games, by about 40 order of magnitude, than atoms in the observable universe. To solve chess, you’d have to map them all. Good luck.
Elon: Wrong, all legal chess positions are ~40 ooms less than the estimated atoms in the Universe. And ASI will figure out ways to solve and compress that are far beyond what we could possibly comprehend. (Here I am arguing with some random intern at a chess website)
Chess.com: I’m a full-time employee
Elon: (something-emoji)
Chess.com: Even my friends don’t text me back that fast

I love how everyone here is like “hur hur, Elon is a moron” (and of course he is).
But in the end they’re just talking around each other. And are both right it seems.
The number of atoms in the universe is about 10^80. The number of possible games (which the chess.com guy was talking about) was once estimated to be about 10^120 (so 40 magnitudes larger). The number of possible positions is currently estimated at about 10^40 positions (so about 40 magnitudes smaller).
In the end i’d say positions is more important in solve a game than ways to get to those positions. For each position you need to know the perfect next move.
But Elon not noticing he’s talking about something different than the Chess.com guy is… intriguing XD.
I suppose Elon is semi-correct when he says that the total number of positions is less relevant than the total number of positions reachable if one player plays optimally, which will be orders of magnitude smaller. But that’s also kind of impossible to calculate unless you know what optimal play is already.
tbf even if they did notice, there’s very little point with arguing with a chess.com
internfull time employee who’s proably very annoyed so it would probably just be a waste of time to point it out.