Amen and hallelujah! This is why I gave up on Mastodon. I read that not allowing full text search across instances was actually a design decision in order to discourage brigading. But, more crucially it undermines discovery.
If someone want full-text search across the entire fediverse, who is going to pay for it? Bluesky has a business model that makes that attractive to them as a value add to pay for. ActivityPub has instances running on RPis in a shoebox. (This is a great thing, it's part of where ActivityPub federation works well.)
Of course, that's also before you get into the sociopolitics that many instances don't want full text search and are concerned about brigading and pulling old microblog posts out of context for nefarious reasons; some of which is why some instances left services like Twitter and have no interest in services like Bluesky.
The people you describe wouldn’t use Mastodon in a web browser and this is a solved problem on the apps.
The only person I know who regularly uses Twitter says she has never visited the site in a browser and is quite sure that everyone in her circle uses the app. But that's just anecdote
Stay with me...
So: federation is very cool in principle, and it's extremely cool in that it in theory means we don't have Just One Batshit Master of all our content... but in the way it's being done with Masto, it IMHO makes for a weak proposition.
Why?
Mainly because people (normal people, not us lot) don't understand or care what "federation" is. They expect (because it's been the norm for every other service), a SINGLE place where they can go to find their mates and celebs and politicians.
What they instead get is a thing where:
1) They can't search a global place and find all those people they want to find (why the Mastodon team don't have this as the #1 thing they are working on, who knows)
2) They find someone on one "instance" (not understanding what an "instance" is) and then can't (easily) follow them from their own instance without having to think about namespaces and all that
3) They naturally gravitate towards the biggest one - probably mastodon.social - and then we're right back at the beginning, with everyone on a single instance, beholden to the possibly loony who might shut it down / monetise it / etc
Moving between instances is much harder than it is claimed to be (you lose all sorts of stuff like your history, or at least you did when I tried it).
Federation also brings all manner of hard things to those trying to run an instance - I tried, as "medium level nerd" and ended up walking away from the complexity of just not understanding why some content didn't seem to be getting from my instance to others, etc etc.
If I was the Mastodon team, I'd be focusing all my attention on global search, and on never using the word "federated" in any of their marketing ever again. It might well be the coolest thing, but it's a non-marketable thing.
Of course all this is predicated on "a good outcome" being "everyone on Mastodon" and I do appreciate those who don't want that. It's definitely the case that less people tends to make for better online social spaces, and maybe small niche groups leads to better things all round.