To be honest, it might be desirable to have 1 address where all EU authorities are active, so that it is clear that you are dealing with the real parties.
I agree with the problem, but not with the solution. We should not use domains as an identifier. It’s too coarse, it doesn’t scale and it’s very insecure.
If we create one large server for all European government, it will house thousands, if not tens of thousands, of clubs and organizations, because there is simply a lot of government. That makes it a lot more difficult to keep it secure (the more people, the more chances of a password leaking) and it becomes a gray mass of vague authorities, so you still don’t know who is really important.
Domain names are also not secure because anyone can register them and because typosquatting cannot be prevented, you can quite easily get a domain that at first glance is indistinguishable from the real domain. “nationa!eoverhe!d.nl” or something like that.
I am a big supporter of better means of identification on the Internet, but I don’t want it to depend on domain names, it is too easy to fool people with that.
This is not to say that I have the ideal solution ready, I know of various options but they all have their own disadvantages, but relying on domain names is not enough, especially for something as volatile as social media where people do not have more than a few one second of attention per message.