After a factory reset the restore of SMS, call-history etc. fails I turned on &quot;backup to google drive&quot; using an account on a &quot;legacy free edition of Google Apps&quot; domain and then factory reset my Pixel 3. When I worked through the re-configuration, at the very end, the restore failed with a message saying &quot;Couldn't finish restoring the backup&quot;. Several attempts at re-running this didn't change anything.
My working theory is that the failure is due to the default installed version of the apps in question, after a factory reset, being older than the version that created the backup before the factory reset. What is needed is to defer the restore-from-backup (which seems to be impossible to directly trigger once the initial setup is &quot;done&quot;) until after they are all updated.
What ended up working was to do the following:

During the initial setup bypass adding an account at all and defer as much setup as possible (remind me later, skip, etc.). As soon as possible, get a home screen. (I just left the setup screens idle in the background.)
Once at a basic home screen,use the app update screen and prompt an immediate update of everything,
Wait for those updates to completely finish.
Then, add the primary account.
Finally, resumed the setup, hope and pray that that it will now attempt the restore from backup using the newly added account.

I'm likely missing a number of details so you may have to try this several times to figure out exactly what things take.
Another thing I did, which might have an effect, was to restore only the thing I actually needed, ... but my gut says that wasn't the big difference that made it work.