Reddit 上有个非常好的回答

Having tried both (and Dioxus too), Tauri seems to me a better choice.

The release candidate they released is pretty solid, tooling is great (create-tauri-app), communication between frontend and backend is very simple (it's just a macro, it supports async, and everything that implements seeds::(De)Serialize can be sent/received), etc.

Also, since it uses web technologies, you get all the existing ecosystem, which is huge. It's unbeatable.

Flutter is great for mobile apps. For desktop, there's still a lot missing. Performance is also very poor (honestly wasn't expecting that, might have something to do with my hardware thought).