There is no digital sovereignty without ODF

Any other choice is a choice of dependence on a single vendor

Digital sovereignty begins with the document format. Everything else – server location, hosting jurisdiction, procurement clauses – is downstream of this single decision. If the format is standard and open, the user controls the document. If the format is proprietary the vendor controls it, even when the file sits on the user’s own hard drive.

https://blog.documentfoundation.org/blog/2026/05/15/no-digital-sovereignty-without-odf/