MMM is a valid 3-letter word in Scrabble (Collins Scrabble Words 24 list). The family oriented MUMMY, DADDY and NANNY have already been used and I think repetitions have so far never happened. Decision time will eventually come when the limited Wordle database (less than a fifth of all 5-letter words) is exhausted.
I am always wary of the possible American flavour (should say flavor) as the game is managed by the New York Times. I wasn't aware that FRITZ from the other day was anything other than a man's name. In consulting the archive I noticed GOLEM as a solution I wouldn't have known if I had competed that day.