Both are good, depends what you are looking for. As a retiree for whom every dollar counts, I prefer lichess, but both sites have plenty to offer. Ratings on lichess are absurdly high, and most of the people I know are on chess.com. Chess.com social structure accommodates teams more readily. But I do like unlimited tactics, opening explorer, game analysis etc. on lichess.
If you don't mind spending some money why not use both? Nothing says you have to use one or the other exclusively.
As an aside, this reminds me of the old debates about ICC vs FICS and similar arguments were made.
I found a way to pay cheaper for diamond membership in chess.com. I think chess.com is the best one of all.