Google's Files app on Pixel phones has a Smart Storage feature that helps you free up storage space on your phone by automatically deleting your backed up files after a certain period of time. This way, you don't have to manually delete files you've already uploaded to Google Photos every time you run low on storage space.
How to delete photos from Google Photos without deleting them from your phone
In this post, we'll explain what Smart Storage is and how you can use it to delete backup media from your Pixel device.
The Smart Storage feature in Google's Files app lets you permanently delete media from your phone that's already been backed up to Google Photos. Smart Storage can help you clear your phone's local storage by deleting media that's already been uploaded to Google Photos' cloud servers.
When you turn on Smart Storage, the app will delete all photos and videos backed up to Google Photos: