This is likely an unpopular opinion, but the extent to which current solutions are decentralized actually makes it difficult to gain critical mass. When watching others (previous Twitter and Reddit users that are not very tech savvy) try and use Mastodon or Lemmy, it's very clear the idea of federation still is pretty foreign, despite having used it in email for a long time.

I think OP has a very valid point: providing a better experience through the illusion of centralization could be beneficial to transition users to the Fediverse.

And this actually doesn't destroy the whole purpose of federation to begin with:

It's clear with Apollo, RiF, Tweetbot, and every other "third party" social media client that the actual interface is often fungible and there's enough demand-- when the social network is large enough-- to support multiple, high quality clients.

Reddit isn't dying because of the interface itself, despite the app and new website being terrible user experiences. They're running into challenges because they are upsetting the user base by exerting control over the content. Yes, you now must consume Reddit through the official interface, but it's not the interface itself.

But federation is not about the interface, it's about distributing the content in a way that results in a network that has no single authority over it. Regardless whether one particular UI or app does something unpopular, your content is all safe on your server and federated to others, and you can simply switch.

There's obviously still challenges if "mastodon.com" provided a "centralized" UI and literally everyone gravitated towards it (it makes it harder for the critical mass of users to migrate later), but they don't actually ever have control. In this scenario they may have more mindshare, but federation makes the network (and its most important asset: the content) resilient as a whole.