Some programs have a ~4x slowdown. That's also not super common, but it happens.
Most programs are somewhere in the middle.
> for the use-cases where C/C++ are still popular
This is a myth. 99% of the C/C++ code you are using right now is not perf sensitive. It's written in C or C++ because:
- That's what it was originally written in and nobody bothered to write a better version in any other language.
- The code depends on a C/C++ library and there doesn't exist a high quality binding for that library in any other language, which forces the dev to write code in C/C++.
- C/C++ provides the best level of abstraction (memory and syscalls) for the use case.
Great examples are things like shells and text editors, where the syscalls you want to use are exposed at the highest level of fidelity in libc and if you wrote your code in any other language you'd be constrained by that language's library's limited (and perpetually outdated) view of those syscalls.
It’s a typed shell. So you can do jq-like data manipulation against a plethora of different documents. Unlike Zsh et al that are still ostensibly limited to just whitespace-delimited lists.