Google actively scans your documents on drive and will lock you out of documents if their algorithms decide you're being naughty.
Many writers have reported having this happen to them.
quoting**Introducing Docs in Proton Drive – collaborative document editing that’s actually private**
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"Today we’re announcing a new end-to-end encrypted, collaborative document editor that puts your privacy first. Docs in Proton Drive are built on the same privacy and security principles as all our services, starting with end-to-end encryption. Docs let you collaborate in real time, leave comments, add photos, and store your files securely. Best of all, it’s all private — even keystrokes and cursor movements are encrypted."
https://proton.me/blog/docs-proton-drive