Because of the back-rank mate, retreating to d2 is impossible, and so White loses material. After

White has to surrender the exchange:

Black is winning easily.

Black is insufficiently developed, and this circumstance allows White to land a tactical blow:

The knight cannot escape from the pin without serious material losses.

On 17...f6 or 17...Ke7, there follows 18.Rac1.

Is Black defending? No, his pieces are tied up, and White has a pair of passed pawns, which are ready to promote.

He has to bring the rook into the game in this way, but Black does not solve his problems.

And White won.

All the black pieces are extremely passive, and the Na7 creates a sad impression also. Not surprisingly, as well as possibilities of increasing the pressure gradually, White has an energetic decision: