packages installing but not working due to missing dependencies

This is the fault of the package author/maintainer

packages installing but not working due to broken dependencies

Sometimes the fault of the package author/maintainer. Sometimes this is the fault of a different package you’re also trying to use in tandem. Ultimately this is a problem with the shared library approach python takes and it can be ‘solved’ by vendoring within your own package.

packages not building and failing with obscure errors

Assuming the package is good, this is a problem with your build system. It’s like complaining a make file won’t run because your system doesn’t have gcc installed.

one package was abandoned and using Python 2.7

Unfortunately there’s a ton of this kind of stuff. I suppose you can blame pypi for this, they should have some kind of warning for essentially abandoned projects.