Free and Open Source Software

foot... Searching for it

euro office... searching for it

Whether you like the SEO-driving search engine providers or not, they are still the way that most people find things on the internet, and they prioritize Github results. When you're not searching for "it", but just searching them by describing things like it, (of which there are many, mostly on Github), it serves your interest to 'O' for the 'SEs' by putting it somewhere that will get prioritized higher.

If the goal is digital sovereignty for europe

Sovereignty is exercised and evidenced by a state's ability to enforce the laws they have created. Microsoft operates within Europe. As long as Europe can enforce their laws upon Microsoft (as they can and do now), that relationship is still an exercise of European sovereignty.

Back to my first comment in the thread, "sovereignty != isolation". Cutting yourself off from external groups does not make you "more sovereign" or something. If Europe cannot enforce their laws upon foreign business entities operating in their jurisdictions, and thus choose to prioritize Europe-headquartered businesses, that would be evidence of far weaker sovereign control of their jurisdiction.

Now, if it's just a matter of prioritizing supporting European businesses, (call it, say, "Europe First", or maybe "Make Europe Gr..." oh wait) that's fine for them to do, and supporting any smaller business or organization over a large one is almost always preferable, but that isn't and shouldn't be about the perception of sovereignty or about nationalism, it should be about fighting back against corporate power by not rewarding these de facto monopolies and political meddlers and manipulators with your business.

But once again, that's not within the scope (or ability) of a simple Office-alike application.