So the user is just stupid eh 😉

Not sure I have said that. I think the problem is users somehow treat software different. Explaining them advantages of federated services over the corporate silos is something that will help them. I am talking about education and not that someone is stupid. In that sense everyone is stupid because you never know everything.

It's like choosing a linux distribution. When you know how the fediverse works, it's easy, but when you don't, you don't want to hear that "it's just like email!!". Why not? The fundamental understanding of how something works is important. I was that person in the past and understanding the idea of distros and abundance of choice is what drew me into Linux (20+ years ago). I don't see why this should be avoided, but even if, there are major ditros that are ready to use out of the box which most of the new users endup using.

It has to just work without any kind of choice what so ever,

Why? Why does it have to work like this. Why is email working differently without the problem but other things do not. How do you want to resolve this in services that use FEDERATION as the main selling point. Randomly assign new users to servers? This will either lead to dumping people on servers that are unstable, totally alien in terms of local content or if you want to be the safe side and assign poeple to established big server, contradicting the fundamental core feature of decentralization. It's like expecting every single alternative to be the exact clone of the big corp. Why not add algorythms since otherwise people might find it hard to discover content, why not more funding through VC or ads to compete with big ones marketing product. This can't be the same as the corp. stuff because it has been created to be different. And it's not that peopel are stupid and thats why they dont use it. Majority of people did not hear about the alternative and/or do not see the benefit it brings.

Also IMO it does "just work". And is pretty slick as a default if I compare it to the state of federated services 15 years ago. It's pretty convenient if you just want to use it. It's not like you NEED to spend days researching servers. Mastodon's main landing page provides onboarding to that. IMO the problem as your Signal example comes down to the fact that big corp operates with marketing budget that is no match for anyone, even Signal. This is the main reason it does not gotten traction. I just hope people will see the added value in community hosted services.