1) The problem with teaching is that "filler" often isn't.

Teaching is art and not science in spite of what so many tech folks think. If I'm teaching a hard subject, I don't know a priori what will click with each student. I'm trying to give you multiple tools for you to try to use while working on problems to get you to your next level of understanding. Some of those tools are idiosyncratic to my experience and not in the textbook. Most of my suggestions are going to wind up being useless to a particular student, but I'm hoping that at least one of them connects properly.

For example, the biggest complaint of linear algebra students is "This is boring and doesn't have any use." Well, I can talk about how its used in graphics, but the mathematicians will call that filler. I can talk about solving differential equation systems for the engineers, but the CS students will call that filler. The instructor, of course, thinks all that stuff is filler and would rather get back to teaching the subject, but understands that getting people interested and enthusiastic is a part of the teaching process.

2) The "filler" part of "traditional" media is completely different for each person while "social" media filler is useless to everybody.

This is something that so many people don't seem to grasp. Each individual will fixate on and take something different from a book or lecture. That's good. As long as each part of media resonates and has a purpose with somebody consuming it, it's not "filler".

The problem is that "social" media rewards behaviors that create useless "filler". So, social media is in a war--people get more sensitive to ignoring useless filler; the social media sites ramp more aggressive garbage; people get more sensitive; lather, rinse, repeat.

The problem is that your social media "useless filler" pattern matcher learns to be super aggressive and classifies anything that doesn't immediately engage with you, personally and immediately as garbage. That's fine when doomscrolling; that's not fine when reading a book or listening to a lecture.

That's not to say that there aren't poor lectures or poor quality books. There very definitely are. And you should definitely leave those behind.

However, you need to turn those super aggressive filler filters off when an author or lecturer is genuinely trying to engage you in good faith. If an author or lecturer did the work, is well-prepared, and is making solid points and progress, you need give them the leeway to do their job.