I am convinced that on Lichess there are quite some cheaters but they get cleverer over time (e.g. playing normal and only now and then play engine-supported, so that the accuracy stays<90%). Sometimes I get crushed by a 1500 player. Really? I gave up reporting them, Lichess seems to be overwhelmed and they don´t react, I just block anyone where I am suspicious.
It would be good, if the platform were more open and transparent about cheating and e.g. list how many and whom they ban. For some reasons they downplay this topic entirely. I think chess.com is not better.