Very good question. Makes a decent argument. However to win a chess game, you need checkmate your opponent king so most times you need every piece you can get to do that. Also a rook is 5 points. Don’t u think it would be much needed in the game.

A fair advice it to leave the rooks in d beginning but don’t forget they can be useful and you’d be suprise to know that despite the lethargic nature of the king, it always finds a way to escape. So castle and use your pieces still. The king would be fine or in most cases you can bring them back to help if necessary.