Decryption of files without the client Jeff, it's an interesting question without an easy answer.
The backups are in a proprietary format. Any program that needs to restore these files would have to come from MSP360. I realize that some files may be backed up in whole, and you could make the case that a backup of a file that contains the entire file could theoretically be decrypted and decompressed using some technology outside of MSP360. In order to do that we would likely have to use either some open standard / open source method (like a ZIP files) or provide source code to the community. Unfortunately, that's not how the product is engineered. But even that option would not work with block-level backups, filename encryption, or any new backup formats that we are working on (wink wink) to improve the product.
I suppose we could say that should the company ever go out of business we would make available a version of the product that could be used to restore files. And I'm certain we would do that if this doomsday scenario ever played out (despite our growth and having no plans to go away).
I've been in the backup and disaster recovery space for a long time and the companies I've worked for have made restoring easy, despite them having proprietary formats. And it's more than backup and disaster recovery. You're trusting many SaaS companies with your data for hosted applications like O365/G Suite, Salesforce, password managers, private / public clouds, BDR, etc.
One thing you can do is restore any important files, if needed, and then encrypt them yourself and copy them to cloud storage using a product like MSP360 Explorer. Stick them in low-cost, archive storage or on a hard drive you own and keep them for the long haul. Managing this could be prone to its own issues though.
What have you seen, if anything, from other products that helped relieve you of these concerns?