Python have a 99% compatible jit implementation called PyPy and nobody much know about it. It was production ready since 5 years ago but ignored by mainstream. It is 400% faster than vanilla python on average and Guido and MS is working on for a few percent gain instead of promoting it or eventually making it default. PyPy.org

Even if GvR promotes it fully, it won't be adopted unless c extensions work out of the box.

Python without its crazy amount of extensions in c-api won't survive.

This is something that's up to the community really. The PyPy developers early on made a new FFI that is also available for CPython, sadly not entirely as easy as the classic API but completely functional and if there was a push to rewrite extensions to use that FFI (or provide dual-paths) then the gap could be bridged.

I do hope it takes off.