I use a storage Server with Nextcloud in a datacenter and all the data are uploaded in background.
It costs 16€ ( 18$) monthly.
You can use the Nextcloud app, or photosync.

As another option for backup, I have a Synology with RAID1 and 4TB.
This hosts all my data, music etc and use this one with infuse, too

As a father this turns out the best way. But there is one showstopper. You couldn’t use the photos in appleTV.