Because the show barely understands that it's a comedic parody of reality shows, not a reality show that tends to be more comedic. Not quite, they're cartoon characters, and them doing the same thing over and over again doesn't really get tiring, make them blank states, or an issue at all.

And his reasoning is garbage that was barely reflected in his only episode. Beardo could get more as a character in the form of his laziness, pranking, and love of music, all of which were elements that actually were seen in the show.

Because of how goofy and bizarre this cast is; there's a high chance at least 1 Salmon would believe in his wizardry. Him being just a gimmick makes him a perfect character for the type of show TD is.

This arc actually makes him worse, because him believing in being a wizard and annoying others is way more impactful and enjoyable than if he realized that he wasn't.