I think part of the difference is if you're on a quest for particular knowledge (how to repair your car, how to rebuild a M35A2 winch) vs just browsing aimlessly.

In the first, the internet wins hands down most of the time (there are specialized areas where nothing has been digitized); but the second it's not clear that browsing the library is worse than doomscrolling, even if you're doomstrolling HN or something relatively "high quality".

I think what they are getting at is if you want to actually learn some deep fundamental knowledge on a topic, its still going to be best found in a book today over a youtube video or a medium post. I agree with this. There is a lot of noise on the internet, and all of it is optimized for short form consumption that leaves out a lot of detail. Relevant blog posts you struggle to find due to SEO spam can't compare to a couple hundred page encyclopediac handbook on a given topic. If you want to change your oil maybe you can get by with a youtube video, but if you want to one day cultivate actual expertise you better buy that haynes manual that covers every little system in your car in one place you can easily reference that isn't prone to link rot. You are right that its hard to get good books for certain communities, but the internet comes in handy here, and plenty of good books are available freely online through means of varying legitimacy. If you want to really get a handle on physics, maybe finding a PDF of a good textbook in addition to those youtube videos would go further.