Now we have won the c4-square for one of the knights, which will put pressure on d6 in combination with the g3-bishop. You have two knights: one is going to f5 and the other to c4. That is why Nd1 is stronger!
Finally a knight is arriving to c4 (Ndc4) and the black pawn on d6 will suffer a lot. The black king is also very exposed. Decisive advantage!
and Black is almost losing. We see that ...Bxd5 will not work due to tactics.