Being up the exchange with pawns on the board is normally winning, but the technique is slow: the king must get active, the rook attacks the enemy pawn from behind, and the bishop's side is squeezed into zugzwang.
Rook versus bishop with a pawn each is a typical practical ending. White has a rook, Black a bishop, and each side has a blocked pawn (d3 against d4). The extra rook should win, but only with patience: the tablebase distance is over twenty-five moves.