How Do I Share a Family Photo Archive That Still Makes Sense?
Hand over plain folders with dated filenames. No app to install, nothing to log in to.
The most durable way to share an archive is the least clever one: folders by year, filenames starting with the date, on a USB drive or a shared folder. It opens on any computer, forever, with nothing installed.
Anything that needs a particular app or account will outlive its usefulness. Relatives should not need a login to see their own family photographs.
Takeout JSON Metadata Fixer produces exactly that structure, with the dates inside the files too, so any app they later choose will also sort it correctly. It runs on your own computer and is free for your first 500 photos.