There’s also the issue of beliefs that are traditionally and formally recognized as relating to supernatural and unfalsifiable notions, versus beliefs that are making claims about ordinary material reality.
Throughout human history, most people have had some kinds of non-rational-materialist beliefs about supernatural phenomena (deities, demons, souls, whatever) that have never been supported by conclusive material factual evidence. Such beliefs have been sort of “grandfathered in” to our modern rational-materialist standards for shared practical public discourse in developed democracies.
But that acceptance has been achieved on the understanding that we all expect to treat them as unprovable beliefs about the supernatural—about which everybody’s entitled to have their own irreconcilable ideas—rather than truth claims about demonstrable material reality, which is supposed to provide a common factual and rational basis for our practical policy decisions.
That’s the chief reason IMHO that Trumpist delusional “alternative facts” should not be accorded the same tolerance in the public sphere as explicitly religious and superstitious beliefs. There’s a non-trivial difference between a myth, in the religious sense, and a falsehood, in the secular sense. The latter are not covered by religious-tolerance principles.
TL;DR: If a hypothetical job applicant tells my hypothetical hiring self in the course of casual chat “I believe that Donald Trump is a reincarnation of Sir Francis Drake, which is part of my religious doctrine on transmigration of souls although I know such things aren’t scientifically provable”, I’m going to mentally shrug my shoulders but I’m not automatically going to red-flag that applicant as problematic for my hypothetical company.
But if the applicant tells me “Donald Trump has built an impregnable wall sealing off our Mexican border and won the 2020 election by a massive landslide which was illegally frustrated by vast Democrat conspiracies, and the evil traitorous media are trying to hide those well-known facts from us”, that’s gonna raise an entire May Day parade’s worth of red flags. That’s not just a personal irrational belief: that’s a declaration of allegiance to a full-scale ideological crusade against acknowledging the validity of rationality and reality.