PSL unittest is very explicit and has no magic. Ironically it also has Java written all over it. You must be the first person I met who prefer unittest to pytest.
By “Java written all over it” do you mean that like JUnit for Java, it's an implementation of the xUnit pattern derived from SUnit for Smalltalk?
So, it's maybe not the best evidence that the Python version is particularly a clone of the Java port.
Pytest is very opinionated about how and when it's going to be run. If you want to put a test in say, Jupyter or a Markdown block, unittest is much more amenable to just doing what you want without having to read through documentation to break a whole bunch of magic behavior.