This already exists with F#, OCaml, Scala, Haskell... it doesn't seem to be a big draw.
The effort to make JS work on the server has been much more successful than any attempt to make server languages work on the client. Nothing jumps out to me as an obvious technical reason this is the case -- maybe it's moreso an imbalance in effort & attention?
https://www.compositional-it.com/news-blog/fsharp-react-seri...
It's easy to make JS work on the server like it's easy to make anything viable on the server: it's just one machine running your code, and the runtime only has to interoperate with a well known interface (the OS) that barely changes. And then consider that a web server's interface to the "user" is over a single, abstract port.
In a browser application, you have to interface with JS to drive the UI building blocks (DOM and company). And the web API is async. And you have to build an interactive UI. And abstractions on top of all this are extremely leaky because they are hard to simply paper over and pretend they don't exist like you can on the server.
Often when I see a JS replacement on the browser, it seems to offer very little over JS beyond "hey look, it's not JS" which just isn't enough to justify the penalty.
Finally, the hard part of UI development is stuff like state management and deciding when things should rerender. Switching to a different language alone doesn't give you that. Figuring out a solution in JS, like MobX + React for example, probably does more for you than trying to make a whole new language work.
JS being the monolithic tyrant that other tyrants see with envy doesn't help.
In the server and elsewhere you have several major langs with big enough sub-cultures and a stablished ethos of sharing, even if that mean the second biggest tyrant of C.
JS developers overshadow any other tribe, so that mean that population could have much less exposure to polyglot alternatives.
And then all that libraries, that are made to make sad any FFI you can trow at it.
There are probably tens of thousands of developers waiting in line to switch out JS. The reason they can’t is not even that it can’t run in the browser (many can) but that it interacts with the DOM natively, which makes it the only language that can be used in the browser without masochism. In turn, the DOM is the only UI that is truly cross platform, which makes it the by far best and cheapest option because everything else is either hobby or proprietary in 10 different flavors depending on which fiefdom you build your product in. Basically, JS isn’t popular because of ability, but its interoperability.
The effort & money that has been poured into tech after JS was created would dwarf anything beforehand. Yet, we live today by the open standards that were developed before Bezos etc started purchasing private islands. So I’m a little hesitant to blaming JS for being backwards when the rest of the world couldn’t come up with an alternative despite having 1000x (not an exaggeration I think) more time and money to do so.