+1 this.

Also, when I read about the language features which make Python intrinsically slow, generally I think "I never use that." e.g. operator overloading meaning you need to do all these pointer dereferences just to add two numbers together. Yes, I get that pytorch and numpy rely critically on these. But it makes me wonder...

Could you disable these language features on a module-by-module basis? That is, declare "in this sub-tree of the source code, there shalt be no monkey-patching, and no operator overloading" and therefore the compiler can do a better job. If anybody tries to do the disallowed stuff, then it's a RuntimeError. Would that work?