I just restored my backups a few weeks ago when I bought a new phone. It doesn't work for all apps (I knew it, it's far from the first time I do that) but I am satisfied with the results.

It does help sometimes for retrieving some data manually by digging through the backup files (used it recently for retrieving all invoices from a service that were otherwise only available one by one through a painfully complicated process).

My use case would be to get my WhatsApp database…. Anyone knows if it restores properly?

(Useful even if not … WhatsApp search is abysmal, the db file is much more useful)