Re: Re: Fediverse. My point was more than indeed the Fediverse is more a technical detail than an actual cohesive platform, so it only makes sense to talk about Mastodon, whereas XMPP is more cohesive by virtue of instant messenging being a lot less opinionated.
It just so happens it splits into well-maintained projects supporting the concensus features, and dead or dying projects that don't, modulo a couple contrarians, with a couple more features floating in limbo, having finalized or draft specs that nobody really implements.
That sort of problem isn't best fixed by centralization on one client/server but just certification, which Conversations/ModernXMPP already leads.
As for apps, yes normal people aren't very conscious of what a native app is, but they do feel when their app lags on their older phone, doesn't recieve push notifications, or just looks a little odd in places, which can happen in a one size fits all app. Some of the most popular messengers, like WhatsApp or Telegram, to my knowledge use platform specific tooling, and normal people genuinely appreciate how snappy they feel.
But the issue is more so about developer time. Yes a cross platform app lets you reuse the same work everywhere, but the lead developer still has personal blind spots, and might simply not consider or be able to test things like bespoke Apple workarounds for non-iCloud/encrypted chat push.
Plus it's a communication protocol, like email; we should be expecting people reimplementing it in the weirdest of places. For software like this, the duplication of effort is what drives you to make an elegant design in the first place.