Not all of us obviously. Being average doesn't mean being boring, and he is boring. Not much as character (but this too), but as person in-universe. There are characters whose gag is to be serious and boring, but Tadano supposed to be your average guy. Meanwhile he didn't do anything funny, didn't say single funny line or react to single joke or funny situation in the whole manga. Well, he reacts, but in worst possible way: by playing Captain Obvious. Even in his thoughts he can't think of something funny. Even Komi with her communication disorder trying to make jokes or saying\thinking something humorous from time to time or just acts amusingly because of disorder etc. Real life analogue of Tadano would be the person with no single trace of sense of humor in them
