Overall I am impressed with the PureDarwin project and have enjoyed conducting my research around it. They have achieved a lot, considering that the project is funded by community donations and run by volunteers. It definitely isn’t a production-ready system, but for developers it has the potential to come in very useful.
The PureDarwin team have been able to successfully install MacPorts in PureDarwin, allowing many software packages such as Apache HTTPd, Git and even XFCE to be installed. Unfortunately this is non-trivial to achieve without strong networking support, but it shows the potential use cases of PureDarwin.
The problem with Darwin is that you’re always confined to Apple’s whim; the company has a history of delaying Darwin code dumps after new macOS releases for a long time, not including any ARM/iOS code for almost a decade, and the releases themselves don’t really have a commit history and comments – they’re just big code dumps.
I guess Darwin is interesting from an enthusiasts’ perspective, but as far as Apple goes, they don’t really seem to care all that much about it, other than scoring the occasional good press.