With a written article I can read a bit at the beginning, skim the contents and still get an idea of what it's about and decide whether I want to read more.

Videos are much more difficult to skim or glance over and the beginning is often some boring intro or music or some dudes asking each other how they've been or something equally wasteful of my time.

I think you’re saying this jokingly but it would be an improvement. Most people don’t read the article. This is partially laziness but also has to do with consistency: I know what a Hacker News thread will look like and how it will perform whenever I open one, whereas a lot of the submissions are from sites that are borderline unusable without an adblocker. Posting the full article in the thread would be a vast improvement, but I can’t imagine it would be feasible owing to copyright issues.