It's a pain in Apple Photos that continually nags you about running out of space or buying more. They also have persistent notification badges for settings if you don't turn on iCloud.
If you are backing your photos up to iCloud and you're running out of space, of course you will get a notification. Just disable Photos sync to iCloud if you rely on another cloud like Google Photos
I cannot even use Google Photos in the same way that I use iCloud.
With iCloud I can set the system up to only retain low-resolution versions and only fetch high-quality when needed.
I can't do that with Google Photos. ANY app that requires me to open a photo opens up with the standard iOS photo viewer which does not allow anything. I can't even write an integration for iOS photos so I can browse my NAS, or Google Photos or DropBox or whatever.
But doesn’t the nagging make sense if you’re already using iCloud sync for Photos (so you’re obviously interested in the functionality) but running out of the free (trial basically) space? The badges are crap, yes.