Seeing that Github is exploiting FOSS for its own commercial interests and possibly violating licenses (Copilot), it's not exactly the kind of ownership that I envision when somebody says "own your data".

Don't know much about Vercel, but I'd be skeptical.

I think it'd be an improvement over this project to make those dependencies optional. For example, if I wanted to self-host. I'm using NetlifyCMS for a project and I agree with others that the whole space could use a bit of innovation.