The light-squared Bishop give Black a nice advantage.

There only move to fight for equality.

21.g3? gxf4 22.gxf4 Kh8 and I would not like to be in White's shoes now.

Now there are a couple of interesting ways to play with the black pieces.

Despite having a terrible structure, the position is around equal. Black has a fantastic bishop on e4 and White cannot put pressure along the files. Plan: ...Rfe8, ...Re6, and ...Qe7 unpinning.

A nice intermediate move, attacking the knight, before we protect the e4-pawn. And now Black has a couple of playable options

19...Na6 Another super important moment. Black is simply intending to capture on e4, so how do we stop that?
20.Bd3! Nb8 21.Rc7 Bxe4 22.Bxe4 Rxe4 23.Rhc1 +/- White has a much better position, with a lot of pressure on the c-file and the seventh rank.

20...Rxe4 21.Bd5 winning material.

A natural move, activating the rook along the seventh rank and increasing the pressure against f7.

Winning an exchange once again.