The black pieces are insufficiently active to support the hanging pawns, and White uses a tactical nuance to attack them:

The white knights joins the attack on the central squares.

On 18...Nf6, there would follow 19.Nb3 Nd7 (19...c4 20.Qxe7 Rxe7 21.Nd4 gives White an excellent post for his knight) 20.Rc3, followed by Rf1-c1 – defending c5 is not easy.
Black is prepared to defend the c5-pawn, but White finds a new target in his camp, and switches to an attack on the light squares.

20...dxe4 would leave too many pawn islands in the black camp.
On 20...c4, there would follow 21.Qh3, with the idea of a blow against the light squares with b2-b3.
It was essential to maintain the tension on the central light squares. Correct was 20...Nf6, after which White only has a minimal advantage.

Black’s kingside, with its weakened light squares, is undefended, and White easily develops the initiative.

The Nh7 loses its last hope of coming into the game, and Black has no counterplay at all.

Black resigned.

White’s position is better, but at the moment, the black pieces are harmoniously placed, and are able to hold the defensive lines. The next move is designed to provoke disharmony in Black’s position.

It turns out that Black must weaken his position with a pawn move.

A bad reaction, as now White gets the f5-square, which is too great a concession.

He loses after 23...Rd7? 24.f4+–.
The most tenacious was 23...f6 24.Qc3 Qe6 25.f4 Nf7 26.f5 Qe5 27.Qd3 g5 28.Bg3 Qe7 29.Nc4 Bf8 30.Qe2, although here too, Black’s position looks lost, because of the great number of weaknesses.