Chess: A single move from a game on lichess.org

Yesterday I played a game on lichess, no this is not from the hive chess tournament
rather this game was just a single offhand game, however I chose this due to a single position
where I had a very interesting move, which I played the computer happen to agree with me about the move, but not the reason for the move, so in essence the computer did not really agree, however there was a funny thing where my continuation was actually better than what the computer found, at least according to the computer.

This was the position I had, now I have to find a good move, you can try to see what you would play here, then scroll down to read the rest.

I played what seems like a rather obvious 16.Nf4, the threat seems to be ...Ng6 winning at least an exchange, but then that is easily parried so what makes Nf4 such a strong move?
My continuation was 16.-Qf7 17.Nd3 forcing a clarification about the central tension, I think d4-d5 as also worth considering, but it seems worse, the computer likes a3-a4 with Ba3 as a threat that is also good.