Lichess is great. My recommendation would be to switch over a month so you can see if it has everything you want. You can always use both depending on what tools you like more, i know some people who have a casual account on lichess and another on chess for more serious matchmaking.

As for chessdotcom, i don't really have an opinion since i have not used it much, they are a for profit but that doesn't mean is unethical per se.

What i do know it's that what licches offers is a great contribution to the chess world, and for those who have the means, it's worth to support it. They offer a complete platform for free. This is huge for people without the means to afford a subscription since it lowers the entry to new and young players.

As i say before since one is free, you can use both depending the use case! I hope this helps you, i have to thank you tho, since i stopped playing chess a few months ago and now i itch to go at it again. Cheers!