This is a common misconception and the ratings are not comparable across player pools. lichess starts you off at 1500 and so the center of the bell curve is 1500, chess.com starts you off at 1200, so that's where it balances the 50% at.
https://lichess.org/stat/rating/distribution/blitz
https://www.reddit.com/r/chess/wiki/faq#wiki_my_chess.com_ra...