I cant understand why engine doesnt like Nxe4 at all and considers that white loses advantage with it and prefers Nd5 instead.
But what is knight doing at d5? Isnt it better to get rid of black's good piece?
you don't want let black exchange knights in c3 because it will ruin your structure and blockade your dark squares bishop, but you don't want to exchange them in d4 either because you will activate black white squares bishop to challenge your bishop defensor of castling (in that case engine prefer f3, weakening the structure of castling, rather than exchange them and having a free lift rook for black and easy triple-up on the e file ) so the best move is to avoid changes by moving the c3 knight to the best possible square and in the next 2 moves develop the bishop in b2
d5 is a dtrong square for the knight, it is an outpost on the d-file and on the diagonal h1-a8. You do not want to trade your fianchetto bishop Bg2 for black's Bf5. Usually black goes through a lot of effort to arrive at such a trade like Bf5, Qd7, Bh3. Here you voluntarily trade your fianchetto bishop. That leaves white squares around your king vulnerable. Moreover by trading your Bg2 for his Bf5 you give up your advantage of the bishop's pair. Better Nd5, b3, Bb2 with good play.
Thank you guys, very instructive comments.