Hope not to derail this thread, but there is a ton of UI libraries for Rust. However, I know of no IDE that offers some kind of a form designer like those from RAD Studio or Visual Studio. I have used a simple WebView for small hobbyist projects in Rust (using wry which is also used by Tauri [Tauri in 100 Seconds - YouTube]).
I'm not sure if I'd really miss creating VCL over HTML. I found it very enjoyable so far, however just on a very small scale. If you have heavily invested in custom VCL components over the years, then you're pretty much "locked in". From time to time, I am replacing some smaller parts of our Delphi applications with web interfaces. So far, I am very happy with the results, and I'd like to continue going down that route.