You’re conflating two things here. You said PFI was “not true”. I’m saying PFI is a political and economic idea rather than a natural fact. Keynesianism is a political-economic theory which people can agree or disagree with. Neither are facts.

I meant the argumentation that was used to justify PFI is not true. Theories can be true or false or are you saying that Keynesianism holds not greater status than untested hyppthesis?