The addition of a tagging system to photos in drive would allow people to manage photos of people or places, they can manually tag them. But if there is an API this opens up a whole world of features, like a 3rd party desktop api that uses the drive api to download images, scan them with local AI and facial recognition and apply tags to the photos. Then with a tag search the effectiveness from more fully features photo services can present itself without ever having to let Proton get access to the photos.