The bishop is a worse queen, however the knight has a very unique move pattern and is the best piece for beginners to fork with
Most powerful piece

The knight and queen can be more or less useful in certain positions, but that is positional usefulness.
The queen is the most *power*ful
(Power is supposed to be bold)
The Queen is definitely the most powerful piece on the board because it has the combined power of the Rook and Bishop. So i would say Queen, Rook, Bishop, Knight, and then Pawn. King doesn't really count as a power because, the King is not Generally used to take down pieces.

it depends on the situation if any piece is the best.
I think the bishop or rook can be the most powerful piece.