Where is my data when I backup to Google Drive?

Application data on Google Drive are not stored in your file structure. Daylio app is recognized by Google and given its own place among the apps. You can also see exactly how big the Daylio backup is. Open Google Drive > Settings > Manage Apps. Here you can see Daylio and its size. If you see the number you do not like; you can click Delete App Data. Be careful ⚠️ this will delete your current cloud backups, and you will be left only with your local data on your phone.

The 'Application Data folder' is a special folder that is only accessible by your application. Its content is hidden from the user, and from other apps.