A few years ago, Elon posted (it’s a real tweet; just screenshotting for posterity) that Chess doesn’t have a “tech tree”:
I disagree. First, there’s promotion of pawns. Then, there is castling, which moves the king from a center file to relative safety on the side, at the same time moving a rook into the center and a more active role. And of course we speak of developing one’s knights (who could be likened to indirect fire), bishops (who provide enfillade fire), and rooks by moving them from their starting position into ones where they can more actively attack and defend. the middle of the board. There are even various systems for scoring board position based on piece development. If this isn’t a tech tree, I don’t know what is.