Samsung just rolled out Galaxy Sync, letting you back up your Samsung Gallery photos and videos straight to Google Photos using your existing accounts.
It works quietly in the background once enabled in the Gallery app, so your memories are always backed up without any extra hassle.
Old Google Photos library not imported
With Galaxy Sync, you can see your photos and videos across multiple Galaxy devices as long as both devices are signed in with the same accounts and have syncing enabled.
There is also a handy "Free up space on this phone" option that removes files from your phone after uploading but leaves thumbnails for quick access.
The feature uses the usual free 15GB of Google account storage (shared with Gmail and Drive) and is currently available on devices running One UI 9, with more coming soon.
Just note: only newly synced media shows up. Your entire old Google Photos library will not appear in Samsung Gallery automatically.