Do NOT trust it.
It silently fails all of the time for no reason whatsoever. Check your event logs and you have to drill down to Applications and Services logs, Microsoft, Windows, File History - engine, File History Backup log and sooner or later you will see Event ID 200.
This is the only indication that your backups have failed.
I have fixed this fault 4 times this year already. I've tried using file history on another Windows 10 machine. Same problems. Incredibly unreliable and no warning that it's not happening. Fortunately I have a more robust backup solution for important files.
I would love to understand the mindset of those at Microsoft who think that:
A backup solution should be incredibly unreliable and require an obscure set of files deleting regularly and regular complete reconfiguration.
Not notifying users that their backups are failing.