why is being down a bishop like being down a rook according to the eval?

idk if its just me but when I remove a bishop from a side (specifically the starting position) the other side has an advantage 5.3 which is equivalent to a rook according to the eval

this is because a computer will think ahead and realize that the extra piece can be used to either

A) win more material

B) make the opponent passive (which will effect eval)

C) Damage pawn structure

D) Attack the opponent's king

Of course there is more into it, each piece are not weighted the same every game, depending on where the piece is placed and its purpose in the positon, it will change its actual worth. A knight in the corner of the board may only be worth 2 points, but if it is placed in the center it may be worth 4.

Chess engines consider various dynamic factors such as piece activity, pawn structure, king safety and coordination.

The white queen got that gyat

You can also be down 9 queens and have mate in 1.