The best move that Black can make in this position is to resign. If we put the Black Queen back on g6 Stockfish says that White can force checkmate in 9 no matter what Black does.
So essentially what the engine is saying is, "It doesn't matter what black plays. Here's a move."
After going through quite a few game reviews and being chided by the engine for "missing a move that would win a pawn" (where the advantage I was seeking was positional) I expected the engine to prefer the move that lost the least material without decreasing the chances of a win.
So I was wrong.
Stockfish can't see the forced mate!