A number of governments (France, Germany, Switzerland, Netherlands), international organisations (The European Union, The Council of Europe, W3C etc), public broadcasters (ZDF, the BBC, PBS/NPR affiliates etc) have set up servers or accounts on the Fediverse.
Please ask public services in your country/region/area to follow their lead. I can do a shoutout on @FediFollows to help get them started.
Musk's Twitter hides all its accounts behind a sign-in page, so it's no longer a public channel.
Good luck getting any alphabet agencies in the US to run a Mastodon box. Local municipal orgs might. I'd start with public libraries
Also RSS is great, but good luck getting the average person to use it. Still too techy for most, meh meh.
Oh yeah, grassroots is definitely good starting point There's a US public library at @VernonLibrary for example.
"RSS is great, but good luck getting the average person to use it"
They don't need to use it directly, the main advantage of RSS is it allows mirrors to be easily set up on any social network or website, which can then be followed or read like any normal social media account or site. For example @APoD is a Fediverse mirror of an official RSS feed from NASA.