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Those files are created by "CrashPlan".

Any backup strategy is better than none, but that product is not a very good choice. As you probably know its "home" version been deprecated anyway, so if that's what you're using you will soon need to find a replacement.

I rely exclusively on multiple, redundant Time Machine backups kept offsite and have no non-Apple offsite backup products to recommend. Although I don't use it, "Backblaze" seems to get fewer complaints than others though.

I have used iDrive to augment my 2 backups, the 'real' backups but restoration turned out to be such a chore I stopped doing that, I have yet to find an online solution that is any good. Backblaze is just more of the same as far as I am concerned.

What about Backblaze? 😉

https://www.backblaze.com/

It’s just my preference for kinda “off-site” backup. It’s cheap and have unlimited space.

Have you tried to restore one yet, making a backup does nothing of value, restoring it is what matters. Erase your Mac and restore your Backblaze backup then you will know if it works.