> A Python4 that actually used typing in the interpreter, had value types, had a comptime phase to allow most metaprogramming to work (like monkey patching for tests) would be great! It would be faster, cleaner, easier to reason about, and still retain the great syntax and flexibility of the language.

And what prevents someone from designing such a language?

PSF has full time employees. If someone else does it as a personal project it would remain a personal project and we'd never hear about it.