I imagine part of the challenge going forward would be the hordes of programmers brought up on designing UIs using a DOM, and all the associated tooling.

My prediction is the situation could be similar to how today many text-only programs assumes a terminal-like device. Terminals have been obsolete for years but I personally feel it's a ball-and-chain on text UI development. The web document model could persist long after web browsers are a kind of "terminal" to load and render web documents.

Got it, but if you expect people to switch from JS to Rust , you're going to be disappointed. That's like asking people who just got their driving license to hop into a fighter jet just because it's faster. JS is a simple language. Its widespread adoption is not due only to it being ubiquitous, but also because it's pretty easy to learn. Rust, on the contrary, not so much.