Currently installing cartopy via pip is somewhat painful, e.g. #1035. This could be ameliorated if cartopy had wheels uploaded on pypi for stable releases.

I think adding the pyproject.toml file will separately mitigate #1035, however uploading wheels will allow many more users, who do not necessarily have compilers set up on their machine, to use cartopy without having to setup a build environment.

I've been pretty happy using https://github.com/matthew-brett/multibuild/ to automate building wheels for yt. I'd be happy to give advice about getting that setup for cartopy.

Note that this came up in the context of us adding catopy as an optional dependency of yt, see yt-project/yt#1966.