This reddit post likely has tens if not hundreds of thousands of views, look at the top comment.
Lemmy is losing so many potential new users because the UX sucks for the vast majority of people.
What can we do?
When it comes to software things, I do tend to err on the side of supporting new users - I'll be the first to argue that a person should not have to learn how to use the terminal in order to use Linux.
That said, this situation is honestly bewildering to me. I cannot fathom how the idea of having choices could be considered, let alone by so many people to even make this into a controversy, to be bad design. That's the very thing that makes federation great.
You're all seriously overthinking this. Just look at a few of the most populated sites, and pick one that looks good. The choice makes 95% no difference in practice because on most instances you're going to see all the same content as soon as you press the All button anyway.
One thing I can imagine that would make the experience better, is maybe if there was a one-click way to join or migrate to another lemmy instance, using an existing login. Personally I don't think it's a big deal to just quickly sign up for a new instance if I want to. But I did see that Pixelfed has the option of signing on by using a Mastodon account. So maybe something like that can help?