In the endgame a Bishop can sometimes be good or bad. If your pieces are mostly on light squares and your opponents pieces are mainly on dark squares then you want a dark square Bishop. And vice versa.
You don't want your Bishop to acquire the unwanted label of a tall pawn. This is when it ends up in a pawn chain with its own pawns and can't move. It is quite possible in Bishop vs Bishop endgames that both Bishops can be good or bad. If both are bad Bishops then assuming the two sides are evenly matched, it's a drawn position.
If both Bishops are good then it's game on. If the Queens are still on the board, the Bishops can support them from long or close range. Bishops can support Queens in mating attacks from either wing.