Yeah. And so is JS’s. I think CPython’s design makes it a champ at native interop and a loser at pure compute perf. That’s a valid trade off for lots of important situations.
Are you referring to V8's/Node's C FFI? Why is that extremely expensive?
It's not a trade-off. There's no reason why you can't have a blazing fast and expressive language that also has good C FFI. A single good programmer could make a language that was as expressive as Python (that is, not very), faster, and with a good C FFI in under 6 months.
Aren't you saying it's possible to make a perfect language with no tradeoff, and all that in just 6 months?
No I'm saying it's easy to make a language better than Python in six months.
Then where is it?
You couldn’t be more wrong. Java and JS have expensive FFI because of the specific costs of synchronizing the VM entry/exit with the GC and JITs.