And then there's also crux [1], which is the same "write your mobile app business logic once in Rust", but instead of Flutter, integrates directly with native iOS/Android/Web UIs
Yes, if someone needs to write UI using native Android/iOS code, Crux would be suitable. On the other hand, personally speaking, I prefer to write all code 1 time, but Crux seems to require to write the UI code 3 times for Android+iOS+Web.
Tauri supports mobile platforms too. Sadly, it's not a first class citizen in Tauri 2.0 as promised.
I tried both Flutter and Tauri. IMHO: Tauri is better, because it allows me to use existing web frameworks (or even plain Markdown + Pandoc!), to make web-pages, while handling business logic in type safe Rust.
If you’re doing some super intensive data processing or have specialist use cases then yeah, sure feel free to write that part in Rust, C or whatever you like.
That’s literally what this package is about. Unlocking that use case for you although Dart also has bindings for Go, Java, Kotlin, C, and Swift so you can take your pick.
But the reality is that Dart compiles down to native code on all platforms and is not going to be slower in any way that actually matters or is noticeable to users in the vast vast vast majority of scenarios and the productivity hit you take from moving to Rust or C from Dart is also an order of magnitude slower.
I wasn't trying to be argumentative, and certainly rust is faster than dart, but if type safety is your main concern Dart/Flutter is less convoluted/complicated than rust+web frontend. In my opinion, obviously.
Note that the linked thread by OP has now been resolved and the rinf author fixed and apologized [0]. This thread might be a better start on the differences [1].