It seems like a cool idea. The idea of picking a server to sign up for didn't throw me for a loop like it does some folks; just like email, right? I think it needs a better way to interact on other instances though. Like for this one, I found lemmy.world from a link on Reddit, then opened this post. But I couldn't vote or comment because my account was on midwest.social. So I had to copy the [email protected] community spec from the sidebar, go over to midwest.social in another tab, click the search button, paste the community spec there, re-find the same post, and now I can comment. Ideally I'd instead just be able to comment directly on lemmy.world using my already-logged-in account on midwest.social, or at least go directly to viewing the post via my own server with one click. Functionality like this would probably require a browser extension but that's better than nothing. I actually found one for Mastodon that's supposed to allow something like this for that service but so far I can't figure out how to get it to do its thing, and I don't think it supports Lemmy at all so far.
I totally agree! The tricky thing is that post IDs don't seem to be shared between instances, so it's not possible to just change the URL. Hopefully this is something that can be sorted out.
I went through the same process you did. Created this account a long time ago. Revisiting because reddit is being weird. And, the cross instance functionality and UX really needs an upgrade.