Personally I think that if 'facts' were noticably easier to prove in Physics then we wouldn't have consumed the last third of a century of physicist brainpower

Personally I think that if 'facts' were noticably easier to prove in Physics then we wouldn't have consumed the last third of a century of physicist brainpower on String Theory (et al), blocking students of competing theories from funding/tenure, with no useful results to show for it. The stuff that's easy to prove has broadly already been proved... but... I don't think that's relevant. People have confirmation bias regardless of being shown evidence, it's the central feature of confirmation bias that you interpret new information in a way that supports your pre-existing view. It's a human trait not a feature of the subject matter.