Let me try to put this in terms more familiar to Americans: Could an international agreement that the US ratifies, supersede your constitution? E.g. if NAFTA had a clause curtailing the 1st amendment, would you expect your Supreme Court to concede to it? To allow circumventing the constitution via international agreement?
That's not really a question in a legal system in which judges are removable by a ministerial decree. The judiciary that has ruled this has been installed illegally and is literally pressed into making judgments made by the party elite - regardless if they make sense or not.
Let's not conflate the question about the independence of Poland's constitutional court (on which I would agree with you) with the question of whether international agreements can or should override national constitutions.