I imagine a degree from a Polish university would be all but worthless outside of Europe for most people.
I don't agree. In the USA for example, a degree from a Polish state university can be valued more than from an American university. Polish matura is commonly recognized as equivalent to 2 years of American college. 3 years from the Jagiellonian University gets you easily accepted to any Ph.D. program as a transfer student. With a M.A. from the University of Warsaw you probably have a better chance of getting to Harvard Law School than with a B.A. from Harvard. Polish public universities are very good at teaching, and that is recognized worldwide. However, on the lists of best universities Polish schools don't do well for two reasons. They don't help you find a job. Secondly, Polish professors work in a lazy system which does not force them to "publish or perish", so they don't publish, are not quoted in scientific papers, which lowers the scores of Polish schools. They are not prolific scientists, but good academic teachers. There are thousands of Poles with Polish degrees teaching in American Universities.