> Chess is a solved game. There is always a mathematically perfect move.

This is a good example of being confidently misinformed.

The best move is always a result of calculation. And the calculation can always go deeper or run on a stronger engine.

We know that chess can be solved, in theory. It absolutely isn't and probably will never be in practice. The necessary time and storage space doesn't exist.

Chess is absolutely not a solved game, outside of very limited situations like endgames. Just because a best move exists does not mean we (or even an engine) know what it is