In a world with perfect play this is true, but in the real world there could still be moves that are good assuming imperfect play by the opponent. That's where things get really interesting.

For example I remember the original alphazero model that had been trained specifically against stockfish, would often take a material sacrifice for some advantage that stockfish couldn't see (e.g. sacrifice a pawn, but their bishop gets locked out of the game). I don't know if these moves were objectively good given perfect play, but they could be the only way to win now (chess is very drawish at the top computer level).