It's strange that some people view UIs as being some of the simplest software. Once you've considered the state management, asynchronous nature (meaning your code could be run in many different permutations), graphical elements (graphics' complexity upper bound being equivalent to what you might see in a video game), legacy APIs (old browsers, shims, or old OSes), and IO such as network requests, it ends up being incredibly complex. The number of hours I've seen being spent fighting Webpack are uncounted. From where I'm standing, it's clear the complexity is already there, it's just totally unmanaged.

Rust will make a great UI language once the ecosystem has matured and async has gotten polished more. If upgrading the "Webpack" of the future meant just resolving compiler errors, we would be in a much better world. Same goes for upgrading dependencies on the frontend, which at my company becomes a blocker every 2 weeks or so due to the NPM security advisories being released, accompanied by the total lack of visibility into the dependencies' interplay that the Node ecosystem gives you.