I agree current shared albums solution is too limited. For example (AFAIK) face recognition doesn’t identify people in shared album photos.Missing Feature: Family Sharing
Seriously, doesnt anyone at Apple have a family? If they offer $10/mo for 2TB of family shared data then it should include an OPTION for a family bucket of full-res photos so that parents can choose to combine all/some of their library.
Not sure if automatic sharing of all/ some of a library is a feature I’d personally like, but maybe you can configure an automation for that?