1) Autoplaying videos, especially ads.
2) Pop-ups / overlays.
3) Loading lots of extra elements causing text to jump around.
Especially true if I'm just browsing around and click on something that looks interesting, the above will take that thing from "this might be worth 30 seconds" to "not worth it".
Why kill that little dopamine boost someone just got from clicking on a link to your site? If you're wondering why your bounce rate is so high... though maybe these dark patterns bring in enough ad revenue that it's worth it. I don't see how 3 helps that, though, just lazy coding. Or maybe other people are more tolerant and it doesn't really affect the bounce rate.