Its relatively common in Python for C/C++ code to be shipped pre-compiled as part of binary wheels (for at least the most common architectures). You do still end up falling back to sdists if your Python version or OS don't line up with any of the supplied binary wheels from the author. e.g. take a look at the pre-compiled set for pydantic-core https://pypi.org/project/pydantic-core/#files
