This is certainly a growing trend which was first started amongst end-users themselves, and slowly we've seen a few news media outlets also following suite. So far, only a very few government agencies have actually followed. Coming to mind are also The Netherlands. What is attractive for many organisations and agencies on Mastodon, is that...
The EU itself also has a Mastodon instance with the funny, overly clear name of https://social.network.europa.eu/
But only the institutions of EU, not for EU residents.
I like this idea because it becomes very easy to verify authenticity especially now that verification badges on X is just subscription badges without verification. You simply set up a subdomain of the form social.country.tld (much like the German parliament did) and you’ll know forename.surname@social.country.tld is an authentic representative for a political party or whatever. No money involved other than running the instance, which will be a tiny cost for something as niche as one offering a voice for the parliament alone.
So I hope this takes off even more around the world. It is certainly a more democratic way to do social than paying some dude in America that runs his personal garden to have badges.