Blue Sky “fixed” that by only having one instance.

I suppose we could “fix” it in a similar way by inviting people to a specific instance instead of pointing them at join-lemmy.org.(Although that site has improved massively since the last time I saw it.)

Don’t even mention instances or federation, just say “hey you should join me on <favorite instance URL>”.

Once they are using it, that’s the first hurdle, and they’ll notice pretty quickly that there are other servers that all (mostly) talk to each other.