I think it's a matter of priors. If a Youtuber shows, say, how to make non-Newtonian fluid from starch, then it's much easier to accept it at face value, because we already know such a thing exists, and what would they gain by faking it.
On the other hand, if another one shows room-temperature superconductor which may or may not actually exist, then (1) we don't know if it's true yet, and (2) it's pretty obvious why someone may want to fake it to get their five minutes of internet fame.
On the other hand, if another one shows room-temperature superconductor which may or may not actually exist, then (1) we don't know if it's true yet, and (2) it's pretty obvious why someone may want to fake it to get their five minutes of internet fame.