A restore point is a snapshot of system configuration: installed drivers, registry settings and program registrations. It is not a backup of your documents.
That scope is exactly why it is useful after a bad update or driver installation. It puts the machine back to a known state without touching the files you have created since.
It also explains what restore cannot fix. If the problem is a corrupt document, a full drive or failing hardware, rolling back configuration changes nothing.
Restore points are created automatically before major changes, but only if the feature is enabled and has disk space allocated to it.