Sure, maybe we'd see huge pragmatic gains after everyone was (for example) an atheist for a century but there just aren't smaller gains to be realized from atheism at smaller scales.

My inclination is to distrust anyone who claims that the theory they advocate can only be tested by an apparatus too impractical to build, and is necessarily untestable on any scale small enough to actually test... but I concede that it's possible.

And agreed that my examples aren't good analogies for that sort of situation.