I can’t stand stereotypes. There’s so many that I can’t even name all of them. It’s okay to use stereotypes, but there has to be some sort of an element added to it to make it more “original” and “creative”- otherwise it has zero substance.
Perhaps I’m incredibly picky, but I will tap out of a story the absolute moment a character says something that’s unrealistic and forced. It’s annoying, real-life isn’t like that, and it overall loses substance. I love reading stories where the characters don’t have perfect dialogue and it flows naturally- it makes the story feel more personal, real, and therefore increases my engagement.
Directing makes a huge difference to me. If there are a lack of zooms, overlays, music, etc., then I’m not as interested- it’s as simple as that lmao
Last “big thing” is grammar and spelling- if you don’t know the differences between “to,” “too,” and “two” or “there,” “their,” and “they’re,” you don’t capitalize “I,” you don’t use “a” / “an” correctly, or anything else in that realm, then get your story out of my face 
Obviously people make mistakes when writing a script, but constant mistakes are a fat no 