If you don't have the urge to jump off a hill when you see heavy pragmatism, Typescript is very popular and well maintained. My experience is only positive.

I was also wondering, does Blazor work with F#? That could also be an option. Not a front-end focused language but a front-end focused framework, so, there's that.

I truly believe TypeScript is the only true way forward for frontend web programming.

Now what we really need is a functional dialect which compiles to TypeScript...

TypeScript or Flow for that matter sucks at using functional style with immutable data types. There are ESLint plugins that allows to enforce immutability with plain JS objects, but still lack of syntactic sugar or union types makes the experience much worse then in functional languages.

Only stage 2, so whether it'll get through to next stage is up in the air, will depend on interest (compare to Temporal which started fairly slow but has gained huge momentum recently and is now at stage 3 and engine testing level) but it's encouraging.