heuristic: Nb4 one move earlier is interesting
17...Nb4 18.Rfc1 (18.Bc4 Rae8 19.a3 Bb6) Nxd3 19.Qxd3 Qg6
21...Re3 is odd. Does BLK want an easy endgame win (22.Rxe3 Nxe3 23.Qxg6 hxg6 24.Rb1 d3). The other piece to e3 seems better 21...Ne3 22.Qxg6 hxg6 23.Bc1 Bb6. and Fritz found that Bb6 now (instead of 24...Bb6) is powerful (21...Bb6 22.a4 a5 23.g4 Ne3)
with 22...Rxh3, does BLK want to go to the endgame now? because Bb6 here is powerful (22...Bb6 23.Rxe3 Nxe3 24.Nc1 c6 25.Qc2)
and when Morphy finally plays Bb6, he misses 24...d3 and WHT's game is desparate. (25.Be5 Bb6+ 26.Nf2 c6)
maybe the "passed pawns must be pushed" exhortation was not common back then, but instead of going after the K with Re8, 23...Rd8 24.Nxh3 d3 25.Nf2 Bb6 seems better.
and 26...Qg4 seems (to me) to be another one of the "pressure the K at the expense of a better game" moves.
26...Qd6 is a crushing "quiet" move. nothing stops d3. then again, maybe pushing passed pawns was not dogma back then.
on the other hand, the final sequence is sweet! 27...Qe2 is another one of those "attack the K" moves, but this is so crushing. I would have opted for 27...Qxf5 and coast to a safe win.
Morphy's persistent pressure against the K is instructive to me.