And that's just the top-level differences. It gets worse as you get into the details of API style and the costs of the indirection layers to convert into the local style, assuming conversion is even technically possible.
Even if you write with the lowest possible common denominator of C or Rust with no runtime, you'll still encounter a significant subset of those issues. And of course we still will use such things; all serious languages can communicate in some manner with a C implementation of a library. (Not for any theoretical reasons, really, C has more opinions than people often realize, but because it's still the baseline current systems are built on.) But it can't be as good as a native implementation.
Heck you will encounter those issues in a large project using only one language!
A lot of language specific libraries incorporate foreign language (often C) libraries and add additional functionality thst fits the ergonomics of the target language, rather than being a thin wrapper around a language neutral library. This is more than aesthetic when the target language has, for example, differences in type system or fundamental guarantees from the underlying library's language.
OTOH, sometimes there aren't C (etc.) libraries, and it's more straightforward to implement a library in (say) Python. But once you have a Python library, calling into it from Rust, C, Erlang, or even a broadly similar language like Ruby is, to put it mildly, non-trivial.
You mention Python that they say has an easy FFI with C. That's nice but it's usually used for the performance more than for reusing code.