Might be related to NixOS being strongly related to Netherlands and them picking local
Constituent states rightly can choose to make their own decisions in matters like this, it hardly effects anyone else, and they can choose to collaborate.
How is that in reverse to what I said? I said the same thing, and explained why this isn't actually happening.
Yeah but when it comes to national sovereignty you can't let your own products get steamrolled by the entrenched monopolies of your adversaries (Google, Microsoft, AWS, etc) just because you're gullible and still think you can play by the rules of idealistic 'free market' and come out on top, while your adversaries protect their monopolies to weaponize them against you on the "free market", suppressing or destroying your domestic industry and making you indefinitely dependent on them (US big-tech, Chinese EV industry, etc).
China has achieved a SW industry superior to the EU with much less money, simply because it has banned US big-tech from its market, preventing its own small domestic players from being crushed by US giants. It's also how countries like Italy, Japan and Korea built strong car industries post-WW2, as they banned superior import cars (often US ones) from their markets, till their own industry could catch up and be competitive internationally. India does the same.
The problem has more to do with the weak sense of belonging to a supranational identity. Californians and New Yorkers both identify as Americans before they identify as members of their home state; the opposite is true of most Europeans still. Change is slow.
You don't need to completely erase and crush ethnic and national identities in order to standardize on technical platform for the common market.
No you don't need that, that's why we have the EU & EC that just demands all members follow a fixed set of rules and regulation in order to solve a common problem. Operating systems could also be part of that problem to solve (amongst million other sovereignty problems we have to solve but will never get to).
You didn't need a shared sense of belonging for the EU to mandate USB-C on all gadgets sold in the EU. So you don't need a shared sense of belonging to demand all EU government systems transition to SUSE or compatible forks in the next 10 years, and each state can fork and modify it to its own liking by local companies and service providers to support its domestic market/industry if they wish.
If EU countries can build Airbus planes together, then they definitely can standardize on an OS, you just need to want to do it, but unfortunately, the politicians and policy makers who helped put Airbus together, were cut from a different cloth than the self serving useless rejects we have today at the EU helm.