Elena put their finger on an especially weak spot for Lemmy and PieFed, where Mastodon integration is somewhat of an afterthought. There is some integration but it doesn't really work the way they expected it to.

The ideal of "everything talks to everything" still remains elusive.

These days I'm less sure it's even a good goal to have - content on different platforms doesn't always 'fit' in others. Mastodon posts lack a title so look awkward on Lemmy, Wordpress blog posts are often long, causing some Mastodon mobile apps to make their users scroll for days, Peertube videos often have a bunch of "here's how you can give me money" links in the body which look spammy out of context, etc.

Some platforms are a more natural fit for each other than others.