Unless your a Grand Master, chess.com is unpredictable with the level of play a player possess. No matter their rating, the player can be considerably advanced. Lichess is better when seeking a comparable opponent. Chess.com expects you to play as black even when you've already played as black. Win or lose it should alternate especially if you protest by aborting a game or two. Rather chess.com will INSIST you play black and view you as abusing for insisting to play white, which you won't get. Lichess will alternate your color if you protest playing a color you just finished playing. Today is my white practice, but 80% of my games are my being black. Hacks, cheats and abusers are more frequent at chess.com. Overall chess.com the is most popular, and the most difficult opponents.