Can I move pictures from my iCloud library to another I have 200G of iCloud storage and about 120G of it is about 12,000 photos. They are all in my account.

I want any pictures anyone in my family takes to make it into this list. However, the only way I can figure out how to do this is to put my iCloud information as the primary iCloud account on all devices, which I don't want to do. I want each family member to use their own iCloud account (which is connected to mine via the family settings.)

To be clear, I want this to be totally automatic, just take a picture and it's everywhere, which seems to rule out shared photo libraries.

Is there a way to do this?
No. You'd have to set up your iCloud account on their devices as the main account to use for pics, find my iPhone, backups, etc, and then set up their iCloud account as a secondary for email, notes, mail, and iMessage and FaceTime.  Unfortunately that's the only way.