Basically, not sure how Apple does it though. You have a Google family group. You can add individual accounts to that. The group owner cannot see any activities of other accounts, but he could remove people without their permission.
Removed users only lose active family subscriptions like youtube premium and google one (storage). Their watch histories and whatnot will remain the same. Watch out with Google one. If you have Google one and use more storage than google free, then remove google one, you only get a limited time period to remove data over the limit. Afterwards it gets inaccessible, I don’t think they delete anything, but no insurance on that.