When everything else is traded, the side having an extra rook and pawn is the only one with winning chances. The pawn can promote, and can have good support from the rook, while B+N just barely win against even a naked king.
Those two light officers are going to cause so many problems for the entire game up to that point, giving the side down a rook attack opportunities, chances to win pieces, and probably a good numbers of pawns. Ouch.
To exchange a bishop and knight for a rook and pawn, you need a concrete follow up. The endgame is too far away to be a concrete follow up.
Example of a concrete follow up:
[title "Bishop and Knight for Rook and Pawn"]
1. e4 e5 2. Bc4 Bc5 3.Nf3 Nf6 4.Nxe5 O-O 5.d4 Bb6 6.Nxf7 Rxf7 7.Bxf7 Kxf7
Black's king is wide open, white's queen is looming, and black's knight is misplaced, easily attacked by the e pawn (8.e5 Nd5? 9.Qf3+ fork, 8.e5 Ne8? 9.Qh5+)