Zip support in cpython stdlib has been there forever (I think it might even be from 2.0 times, early ‘00s) but it’s never been very user-friendly or particularly advanced. It’s one of those things like timezone and http, where the implemented API didn’t really come out “right” and there has been some pain ever since. It’s a bit like SSL stuff in JDK: something that should instinctively be very easy just... isn’t.
The library this uses is an old enough bit of python that when I started 12 years ago, I looked at the code and thought the code looked a bit crusty and old.