You don't have to quit Facebook to get the mental health benefits. All you have to do is unfollow everyone! Literally everyone. Your feed will be blank and peaceful, but you will still be able to maintain a presence on messenger and maintain your profile for people to reach you. You can also still interact with private Facebook groups and things, if you want. This is what I did, and it curbed my addiction to checking…
I started just by unfollowing literally everyone. I have since readded my immediate family and a couple close friends. I find this doesn't change things, and it's more automatic than remembering to check their pages. They don't post much.
Finally, when visiting Munich I joined a local group. Didn't unsubscribe, so I still see posts. This is sort of handy: if you have nothing followed, facebook will dresge up random stuff such as suggested friends.
With a single group you auto ignore, facebook is content and just shows that. (But beneath family, if there are any posts from them)