dont like the sound of reimplementing the whole UI components....

You don't have to reimplement them yourself, they already come provided with the same components as on the web, like buttons, forms etc (and there are also custom UI frameworks like forui which clones shadcn/UI if you're familiar with that). The point being, Flutter apps can run much smoother precisely because they reimplement everything rather than dealing with the legacies of HTML and CSS. Since your UI seems fairly simple to make in any UI framework, you could take a look at Flutter as well.

I do so with Rust also with the package flutter_rust_bridge which works great, I'm working on a mobile app that also simultaneously works on web and desktop when I tested it, even all the Rust parts.

> Flutter apps can run much smoother precisely because they reimplement everything rather than dealing with the legacies of HTML and CSS

Maybe in some cases, but I kind of doubt this statement in general. I just tried a Flutter demo from their official site and text selection doesn't even _work_ correctly.

https://flutter.github.io/samples/web/simplistic_editor/

I'll copy-paste a few lines of the example sentence, double click on one of the middle lines to start selecting by word (which it doesn't seem to even do), and then highlighting starts on the top line instead of the line I selected.

In general the flutter apps always feel janky and second-class to the platform they're on, because they never fully implement the exact behavior of each platform they run on.

I didn't see 'highlighting on wrong line', but double-click a word not selecting the word is annoying (Firefox on Windows11)