This one is actually baffling to me. The only dimension where chess.com is better is that it has better players at the very top end... which is not a concern for anybody except ultra-high level GMs.
It's a bit unclear for me how they can provide all the development and maintain the servers running. Are the donations enough?
They're spending ~$34k/month according to the cost breakdown sheet from https://lichess.org/patron, which is about 6,800 $5/month patrons.
They must also have a lot of $10 or more/month patrons.