I'd not say that everything on lichess is really smooth & not laggy, but it's much better than on
chess.com for sure. Also Lichess has free top engine built into the site, free opening books, endgame tablebases, unlimited tactics training, lichess study feature. All of these things are unexistent, limited for free users or pay-only on
chess.com. I remember that the game history of non-premium users is cleared over time as well. Ads are not such a problem if you have ad blocker)
chess.com also has many features that lichess lacks, for example, bughouse, swiss tournaments, 4-player chess, grandmaster blogspot, lots of learning materials, puzzle rush. No reason to hate it too. They have a working business model, which includes asking money for everything, but they actually use these money for good things you might never persuade Thibault to maintain. And the subscription is not really expensive if chess is important for you.