I think you can hide it but not uninstall it. My understanding is the EU's objection is that Photos app still provides the default photo picker functionality when the app is gone; and they'd like Google Photos to satisfy that role if a user prefers. Of course, the EU's approach here is to be coy about what it wants and only make it explicit alongside a headline-grabbing fine.
Or you can install a completely alternative app to manage your photos.
The only thing iOS does in that case is provide the “Album” functionality.