So here is my take on this, once again:

Start with JavaScript. The basic syntax is delightfully direct, it has massive adoption already, the ecosystem is large, the runtimes are getting better all the time, compilation is here with WASM,

Now remove the weird parts (e.g., too much flexibility to redefine things, too much use of the global scope, too much weirdness with numbers, etc.), and add:

- Types (including sum/product types, Result<T>, Maybe<T>, decimals, etc.)

- More functional features (everything-is-an-expression, pattern matching, currying, etc)

- A comprehensive standard library.

Already this starts to yield a language that has the best chance to be what a lot want.

The other major advance in developer tools that I'm wanting to see is revamping HTML to have proper sophisticated controls built-in, controls that can be easily styled with inline CSS. This will reduce the amount of JS needed on the client.

These two things will yield a massive advance in programming productivity, at least as far as web-related development is concerned, IMO

I think this is a really wise take, and one that I honestly haven't seen before. I would certainly try a language like this.

The one thing I would add: Provide a well-trodden path to easily drop down into Rust/C/C++ for performance critical functionality. I have found this to be a big point in Python's favor over Go; you can write things the slow way (ie. executing in the Python runtime), then profile and figure out where to push things down into an extension. Often you're doing something that already exists in a library like numpy or pandas or polars, but if needed, you can write your own extension.

Does WASM enable FFI on its own?

I think here you're pointing at something along the lines of Roc/Gleam?