Cross-posts on Lemmy show links to the other posts on each of them, so you wouldn’t be missing out on anything - you’d just have to click through to the other posts from the one you could see, rather than seeing multiple copies of it.

Their suggestion addresses this:

The UI could detect sibling cross-posts and suppress multiple mentions of the same post if you’re subscribed to multiple sibling communities, maybe with a “cross-sibling post” designation. That way it only shows up once in your feed.

A fair point, and I don’t think the people coming to Lemmy or Mastodon are the people who are happy with the status quo on Reddit or Twitter… it’s the folks who dislike those services for whatever reason, and are looking for an alternative. Lemmy and Mastodon just provide the smoothest point of transition.

In some respects it feels like many federated platforms have approached things backwards, trying to rework a centralized structure to be distributed/decentralized, creating some of the awkward UX folks experience.

I think you’re right, but that this is also promoting faster adoption of the fediverse version of the apps. It’s a lot easier to say to someone, “Hey, here’s a FOSS alternative to this corporate app you already use, it functions the way you’re used to” than “Here’s a FOSS app that does something completely new.”

Once folks are interested in the fediverse through adoption of Lemmy, Mastodon, etc., it’ll be easier to get them interested in completely novel applications.