Cool article, I think a lot of those issues are not Python specific so it's a good overview of whatever others can learn from a now 30 years old language! I think we'll probably go down the JS/TS route where another compiler (Pypy or mypyc or something else) will work alongside CPython but I don't see Python4 happening.

Do you still need an add-on library to use more than one core?

Good job on dispelling the myth of "compiler = fast". I hope SPython will be able to transfer some of its ideas to CPython with time.