Storing important data online on someone else’s computer is beyond fucked up levels of stupid: You only need to lose your encryption key once in your lifetime afterwards, and you can consider your backup public for all the world to see. And a single encryption weakness / backdoor will expose data just the same. Not to mention using third party sw to “do the backup” for you and relying on them to encrypt it so that they themselves can’t read it, is very naive.

Once your data left your home network, it is no longer yours to control.