Why would developers have to interact with a mypyc step any more than the pyc step? Why is “developers might have to interact with it” some kind of non-starter, as though having a compile phase is a worse evil than a hyper-slow language?
FWIW, I think we could probably buy ourselves a lot of latitude to optimize CPython by designating a much smaller API surface (like h.py) and then optimizations largely won’t have to worry about breaking compatibility with C-extensions (which seems to be the biggest reason CPython is unoptimized).
But in general I’ve lost faith in the maintainers’ leadership to drive through this kind of change (or similarly, to fix package management), so I’ve moved on to greener pastures (Go for the most part, with some Rust here and there) and everything is just so easy nowadays compared to my ~15 years as a Python developer.