You just sign in with your Google account and it all does the rest... I mean ffs it takes you 30 seconds and solves most of your problems.

They're unrecoverable because you're not using Google Drive to do backups, dumbass.

It's stupidly easy to recover things with Tabs Outliner. Open the backup, drag and drop what you want.

I've never lost a single tab with Tabs Outliner. I lost thousands with Sidewise. =/