I don’t have amazon or steam so don’t know how any of that works. But for a password manager, family sharing is extremely useful.

Bitwarden doesn’t have families per se, it’s got “organisations”. You can setup unlimited number of organisations and users can get invited and join them. Which is very handy for example my wife and I can login and order our groceries from the supermarket using the same account. Or that we can both login and use our electricity company’s web portal which only allows one account per household. All without needing to send each other passwords and updated passwords back and forth.