I agree that in formal writing, you would probably want to only use it to indicate that you left out a section of a quote. If you’re writing a story, it’s mostly left to your good judgment as to how many are too many. They can help set the flow of a conversation or train of thought, as long as you don’t overuse them.
For example, it’s okay to use the ellipsis in the middle of a sentence to show a pause, or between two sentences.
“It was hell ... utter hell.” Or: “Was it a good idea? ... Probably not.”
What you do not want to do is to start acting like a sloppy fanfiction writer, slapping ellipses between paragraphs to show that the other person didn’t respond verbally.
“Are you okay?”
”...”
“Don’t glare at me!”
This kills me every time I see it.