I've done it a few times. I had one today(the guy resigned after Qg8 but it still counts!)
How many times did you ever get to smother mate your opponent?

Being aware of smother mate threats have helped me in numerous games. Actually delivering the classic back rank smother mate? Maybe only a few dozen times.
Smother mates in general though happens more than you think, I just had two at my local club last week! I think some openings/pawn structures are more susceptible to them though. Strangely, I think most of my actual over the board smother mates have occured in endgames where someone is careless with advancing their king, not so much on the backrank.
I think this is the first time I've ever done this smothered mate. Even tho I've solved it a good bunch of times on tactics trainer.
Have you ever even used this in your life sometime?
Here's the full game:
https://www.chess.com/livechess/game?id=1715751502