https://mozilla.github.io/uniffi-rs/latest/
Mobile UIs are different enough and, these days, easy enough to construct that to my mind there isn’t much value in the cross platform UI proposition these days. But logic? Sure.
There was legit a point where I considered embedding a webview just for the QR code scanning screen, but of course, embedding a webview turned out to be a similar mess.
I now have a separate QR scanning implementation for three platforms and a bunch of if statements in the Gradle files. It took 4x as much effort (once for each platform, plus the work to tie it all together) and now I also need to know how to develop for those platforms, which is exactly what I wanted to avoid by picking a cross-platform toolkit.
This will hopefully improve with time, as it did with RN and Flutter, but my point is that we're simply not there yet.
This bit is obviously subjective, but Rust as a language is simply not ergonomic enough for a lot of the use cases people are trying to apply it to, especially UI development. Most of the Rust UI libraries I've seen to date either use a more imperative style, or attempt to replicate more declarative approaches like Compose UI or SwiftUI, but without the nice language aesthetics that make it simple to read and write. And if the counter-argument there is for LLMs to be reading and writing this stuff, that's a whole other can of worms: (1) The subsidized inference era is quickly coming to an end and (2) if you're using LLMs anyway, why not maintain apps that are as native to each platform as possible?