Was this recently? Unless you're an absolutely exceptional chess player, both Chess.com and Lichess are filled with enough good players that I'd be surprised if you flew through the ranks quickly enough to be accused of cheating :)

You know... no, not recently. I can see from many of the comments here that chess seems to have found a way to mitigate, so maybe I’ll give it another go. Thanks to you and sjcsjc for the encouragement.

I experienced that with Scrabble (and as you, only play with friends now), but not with Chess. But then I'm not very good at Chess (rapid rating c 1300 on chess.com)