Is there something in particular that we are vulnerable to that doesn't also affect Google Drive, Dropbox, iCloud Drive, OneDrive, etc.?
With Google Drive, I choose which files to upload. It doesn't have broad access to everything on my computer.
Dropbox, iCloud, and OneDrive are just backup services, so in theory they could just back up your files as an encrypted blob and have no way to read them. Unfortunately, they don't encrypt them (which is partly why I don't use those services). But at least I have their "promise" that they won't read or analyze my files, which would make me feel better even if its a weak promise.
On the other hand, your service, by nature, is reading an analyzing all of my files using a remote server.
I don't know about the other services, but Dropbox _does_ read your files. https://help.dropbox.com/security/privacy-policy-faq
> We may build models that identify keywords and topics from a given document. These models may be trained on your documents and metadata, and power features within Dropbox such as improved search relevance, auto-sorting and organization features, and document summaries.