I'm sure everyone has their own reasons for restoring & backing up to earlier dates. I've been researching this registry topic for hours, I see the authoritative websites saying it's critical to backup.
I've seen many sites with, how to backup, how to use, etc, though what's puzzling is if the system restore & other backup methods are leaving files & folders in tact what changes are being made to the registry other than the date. And if illegitimate changes are made to the registry, will they be left in tact as well.
Windows native backup has never been a full system backup per se. If you really wanted to revert to a snapshot in the past then you would need to take image backups with a 3rd party software. An image of your drive would allow a complete reversion to the previous state of the system.
A Windows backup is a selective file backup and will not allow a full reversion to a previous state in most cases. Some registry changes may remain after a rollback.