People love talking about how much they hate ads, and how, no, they're not cheap, they would totally pay for content.
Let's be honest - internet users are cheap. They want stuff for free. And if site A starts charging, they will jump ship to site B, until eventually it's a race to the bottom.
Ads seems to be the only model that works (thus far).
Many attempts have been made to monetise things (a la micropayments).
I believe Google did something before, where you paid cents, or fractions of a cent to authors for article views. This was back in 2012:
http://www.bbc.com/news/business-20395407
And recently Mozilla's Brendan Eich is doing Brave, with bitcoin micropayments. I'd love to see it gain traction, but I don't see it going mainstream.
Look, I know some ad networks go too far - but IMHO, Google/FB ads are hardly that intrusive. (I personally hate pop-up/pop-under ads, and auto-playing videos)
(Disclaimer: I work for Google, but not in ads - above opinions are purely my own).