I completely agree with you. Sometimes they absolute noob, sometimes that absolute noob you underestimated see some crazy three move tactics.
I also noticed the difference between the low level Lichess players and the Chesscom players,
The lichess players usually play normal opening, the Italian, london, sometimes the Spanish etc.
The Chesscom players just play whatever, king’s Indian defence,the english, hell I’ve encountered some b4 shenanigans too. 1000 - 1300 Chesscom player are wild.
Wow. In 5 min blitz!!? Amazing. Btw do you have an account now, and what’s your rating?.