Lichess has less of most things. Fewer cheaters is merely the scale. The percentage is likely higher because the resources for rooting then out are limited.
Lichess studies are a great resource. Also useful is an opening explorer that represents all games played on the site. Chessdotcom cannot do that because the number of games played is massively greater.
Lichess has less cheaters. Their rating system is further removed from the FIDE rating system, so less people care about it. Also, it seems Lichess players accept more gambits than decline them. All of their study material is free, you can completely build an opening repetoire there and save it/work on it, or study with others. When a game finishes with someone, you can enter the review board and still chat with the player and can nail down where the game went south for whoever lost etc. They only accept donations, so no money out of your pocket.