There are so many things you want to cut out of you writing, repetition, unnecessary words, filter words, and so much more!
Guess who doesn’t do that? People.
We don’t speak in seventh draft, we don’t even speak in second or third. We speak in first draft and it’s messy and chunky and all sorts. So let dialogue be messy and chunky. Not all the time, it’d get frustrating if it was. But just, some of the time. Don’t be as obsessed with cleanliness in your dialogue, especially when the people talking are on the younger side, because that’s how you get stiff and unnatural sounding dialogue! Natural sounding dialogue might be clean for some characters and messy for others. It’ll be messier if they’re nervous. It’ll depend.
This isn’t me saying not to edit dialogue. Sometimes I specifically edit dialogue to make it sound more messy because a character is nervous. What I’m saying is to remember that dialogue and narrative play by two very different rules!