Keepr Ownership and exit — the two things a photo archive should be least evasive about.
Ownership covers photos that are of you but were uploaded by someone else, and photos of yours you'd rather someone else held. Both directions exist, both need the other person to agree, and — as far as we know — no other app in this category has either.
Exit covers getting copies out and removing things. You can download individual photos, whole albums, or request a full export of everything at any time, on any plan. That's deliberate: an archive you can't leave isn't an archive, it's a hostage situation.