The UI isn’t the problem? The attached screenshot shows people talking about federation. Federation is very confusing, but also the core part of how the Fediverse functions. The only thing you could to is to provide an entry portal, where all servers are categorized by the type of content they provide and you can check and uncheck the type of content you want or might want to interact with. Based on your choices, the portal could recommend a random Lemmy or Mbin instance that has a track record of being reliable and allows you to interact with most content of that type. So if you’d want to see porn for example, the portal should choose an instance that is federated with lemmynsfw.