> Rust, C++, Go, Python, etc. are good, but they're not made for us.

I also don't see any technical reason you couldn't have the best of both worlds. E.g. a dynamic runtime environment that allows recompiling functions on the fly etc., but also have a separate batch compiler that can type check the program as a whole, do whole program optimizations, etc.

So you can do exploratory programming while developing, and the run the batch compiler before committing changes, when doing releases, etc.

I think the biggest challenge is simply the amount of effort required to design and implement it (and of course someone who's interested enough in it to do it).