Shrugs
they are the weakest in terms of they can only move one space and it’s dangerous to put them out on the battlefield early battle.
They are only dangerous if you are close to them/one space away from them. Other than that, they can’t cross an L and jump, they can’t go across the map diagonally or horizontally, they can’t have the abilities the queen has.
essentially they are only capable of protecting themselves or one or two pieces that are probably around.
Compare the king to a pawn, a pawn can at least move front 2 spaces and/or if there’s someone that’s on a diagonal, it can move forward then eat someone on the diagonal square, but if it were a king, he could only move forward and the /pawn/ could take down the /king/
Also, many situations in which a king could actually take a piece, it often puts the king in check.