Well, like the Knight it attacks 8 squares. The weaknesses you mention are dependent on what material the opponent has. Although this has some effect, it is usually pretty minor. (Except for the mentioned devaluation of strong pieces facing weaker ones.) If the opponent had an Archbishop and a Chancellor, a Knight could not fork those without being protected, but a Commoner could.
The main value of the moves is what they can individually do. For things like forking, which depend on the relative positioning of the moves, you need a special pattern of opponent pieces, which will occur only very rarely. An exception could be the ability to attack two adjacent squares on the same file: this allows you to attack a Pawn and the square it could move to. You could also consider that a fork, but the pattern it attacks will be very common, because it just depends on the presence of the Pawn, as the square it can flee to will automatically accompany it, and Pawns are abundantly present. This is why I think there is significantly extra value in attacking orthogonally adjacent squares.
Things a Commoner can do that a Knight cannot, are checkmating a bare King, and destroying an isolated passer if it can reach it. The Knight has better chance to stop the passer, because it is faster, but it will then be bound to stop it. So if on one wing the Kings are bound to the Pawns there, a passer on the other wing will draw against the Knight. If you had a Commoner instead of the Knight it would gobble up that passer, and then come to the other wing to break the stand-off there.
@HGMuller okay, I understand why the Centaur is worth that much, but I still have one question:
why the non-royal King is worth nearly the same as a knight when it can’t even fork a the King and other piece without being protected, and can’t even attack a Queen without being protected and most of the things it can are defensive?
the Knight is a really good offensive piece:
(the King on d4 is not royal)