Proportionally, it might not be much better today. Maybe 1/100,000 books is exactly the piece of information you need. Certainly the rest of the books aren't total crap either, they at least passed that bar of getting the book published and making some sense. I wouldn't be surprised if the signal to noise ratio on the internet today wasn't 1/billion web pages with all the automatic SEO crap and misinformation out there today. The sites and resources you listed are popular in tech circles, but are not mainstream at all. Then again if they were, they probably wouldn't exist as we know them, if at all.