A family of Microsoft word processing software products for creating web, email, and print documents.
It does work, but not the way most people would expect. Google doesn't integrate as well when you take it so far out of its ecosystem. It will not appear as a "place" in Word on iPad like Dropbox does. Instead, you need to tap "More" beside the 3 dots and navigate. By default it will show iCloud, but if you tap "Locations" you can select Google Drive and browse your folders from any Google Account.
You should also be aware that saving to GD isn't as seamless either. While the file will appear to be auto-saving, thousands of users online have reported that they have lost information when they thought it was auto-saving back to GD. I lost over an hour of client interview notes today. It is usually safer to save a Duplicate somewhere in Dropbox or Onedrive and edit that version.