Have you found existing regulation in any field that's evidence-driven?
My impression is that regulation is not made in a way that has much to do with evidence, but I would be delighted to be shown evidence I'm wrong.
It's hardly a perfect system, but the problem is mostly that it's too conservative and risk aware, making it difficult to impossible to innovate and ignoring the risk this creates. (The world's most popular light aircraft is the 1950s-vintage Cessna 172, mostly because it's impossibly slow and costly to get a reasonably priced modern competitor certified.)
Plenty of regulations in many many fields are evidence based.
Sure, many are not.
But to make such a blanket statement is absurd.