QT is already experimenting with rendering to Canvas using WASM in the browser, I've tried to call them out on it as bad practice a couple of times in the past.
Rust on the other hand is doing some genuinely exciting, powerful stuff with allowing WASM to talk to the DOM and allowing native developers to target HTML directly within their apps. Rust's approach is to treat the language like a minimal, drop-in replacement for Javascript that doesn't require you to ship an entire rendering engine alongside it.
It is yet to be seen which approach to web portability is going to win. Obviously I'm rooting for Rust, and I personally think apps that are written using Rust's strategy will nearly always be higher quality than apps written using QT's strategy. But that doesn't necessarily mean that Rust will win, there are a lot of factors at play here. It'll be interesting to see.
But agreed, native apps are definitely coming to the web in some form or another. Funnily, the opposite is also true, since there's been a lot of buzz about using WASM for native sandboxing. I like to think that Gary Bernhardt[0] is pleased about that.
[0]: https://www.destroyallsoftware.com/talks/the-birth-and-death...
