He's talking about "the public sphere." Among the general non-specialist public (probably 95%+ of the population), virtually nobody can even do things like prove the Pythagorean theorem. The idea that science is substantially different from religion for most people because they "could", in principle, reproduce the studies is laughable.

And nobody can realistically reproduce anything outside their own little niche.

"I injected the boys with fluid from cowpox victims, and they didn't get smallpox later."

"I don't believe you"

Turtles all the way down. At best we can say the quacks hold everyone else's evidence to a higher standard than their own.