There are features Python is missing as a scientific language, that are not a focus. Proper multicore support, GIL, any static safety (which type hints sort of address but not really).

It was fine in Python 2, it was cheap and cheerful. It feels likes Python 3 is running out of ideas for improvement, and yet these are not at all in the scope of work.

Cf Julia that treats all these features as first class problems.

I am wondering if this is really a problem? I just parallelized some numerical code and instead of threads (Gil problem), I use processes. As far as I understand the only drawback would be that the parallel items cannot share memory, well do you do that? I find it hard to reason about correctness in these cases.

This works a bit. But sometimes sharing memory is useful. Sometimes you may want to parallelise a local function, or a callable class instance - except you can't.

And when I say, "it works", that's clearly on Linux and Mac. On Windows multiprocessing is very severely stunted by lack of forking.

Meanwhile, probably even my watch supports threads.