Now the bishop is doing a great job in helping his colleague to put pressure on g2.
Giving up the bishop pair in exchange for another advantage: a weak enemy pawn on d6.
Black "messes up" the game before White manages to consolidate, with a long-term advantage thanks to the bishop pair.
If 3.Nb1, preparing 4 f3, then 3...f5! with the idea of 4.f3 Nxg3 5.Nxg3 f4+ etc.
Or 4.Bxe4 Bxh3 5.Bxb7 Bxf1 6.Qxf1 f5! , followed by ...f5-f4 with an initiative.