easily written characters, why bother inventing a new personality, it’s hard to write good characters. just copy already good characters thats easy.
many people rely on cliches and tropes because they can’t be original, I won’t say I dont use them myself because they are hard to avoid actually, it’s not wrong to use a cliche its wrong if it’s not original.
a thing many people struggle with is characters. after all we only have one personality ourself, it’s hard to write diffrent peoples personality. so replying on already existing personalities is a short cut many uses. also in modern tv, for example almost all elves is a copy of LOTR.
many people who write on episode is not experts, and writhing is a skill you build like any other, so newbies often make the clichi and copy paste mistakes.
I look back at a lot of my own old stories, and they are full of clichi and bad writhing where what I write now have very few, and they are used in a way its not really a clichi.
also I really recomand this video about the blond characters Legally Blonde and the History of the “Dumb Blonde” - YouTube