I am a counter example of that take. As a French citizen, I have spent a decade building an open alternative Dropbox [1] that is I believe miles ahead of even Dropbox itself. In practice, France represents about 1% of the customer base. I've tried reaching out to the people who talk loud about sovereignty. Turns out it's just something they say at conferences to entertain each other as they have no power to actually make it happen.

[1] https://github.com/mickael-kerjean/filestash