Some specific examples: When looking up resources on high school level mathematics, it appears that fully half of the content is paywalled. Often this paywalled content isn’t particularly valuable in the first place (eg, hiding a basic multiplication chart behind a paywall)
And a more technical example: when I was learning the Angular framework, damn near all the results on Google were SEO scams. It was content masquerading as tutorials, but when you reach the end (often after investing significant time), they try to extract money from you to read the rest of the guide.
It’s gotten to the point where I’d be willing to pay money to filter out all the garbage from the web.
For stuff like basic math, which literally hasn't changed for a century, I find the old books at archive.org to be very useful.
As for your attempts to learn Angular, maybe Google was doing you a favour ;)
For the maths, look up Eddie Woo on YouTube