2 Answers
allAuthenticatedUsers is anyone with a Google account and allUsers is anyone, authenticated to Google or not which makes the object public. What was the exact error you got for the Google user when tried to access the object?
I found this with a quick search.
All authenticated users – The value allAuthenticatedUsers is a special identifier that represents all service accounts and all users on the internet who have authenticated with a Google Account. This identifier includes accounts that aren’t connected to a Google Workspace or Cloud Identity domain, such as personal Gmail accounts. Users who aren’t authenticated, such as anonymous visitors, aren’t included.
All users – The value allUsers is a special identifier that represents anyone who is on the internet, including authenticated and unauthenticated users.
More information can be found here.