Yes, but I mean... this is Python we're talking about. There are several build systems / coordinators written in Python (scons, colcon, etc) not to mention Python packages that themselves contain compiled bits written in other languages.

I know nowadays we have formalized, cross-platform ways to build bindings (scikit-build-core, etc), but that is a relatively recent development; for a long ass time it was pretty common place to have a setup.py full of shell-outs to native toolchains and build tools. It's not hard to imagine a person in that headspace feeling like being able to pull that stuff directly from pypi would be an upgrade over trying to detect it missing and instruct the user to install it before trying again.