A similar question was posted in the past (2020):
Is there a way on lichess to see the Correspondence chess rankings?
However, that solution is not working anymore. In my perspective, things have changed and lichess.org is allowing correspondence chess, but a ranking does not exist anymore. Is there a way to be certain about this topic?
Also, why lichess.org is treating correspondence chess differently, if that is the case? I am guessing that is difficult to control who is cheating and who is not. In the past I used to play correspondence chess, but I am playing classic games now. According lichess.org classic are games that each side has 30 minutes or more for the entire game. Correspondence chess you have 1 day per move or more. Chess.com calls correspondence daily chess.