The Web was never perfect. There were always people using it to exploit others. Sometimes, it was the small-time Ebay scammer looking for a couple of dollars. Other times, it was a giant multinational trying to get you to buy things you didn't need.
At the same time, it was a wonderful place. You could meet interesting people and talk about anything that you liked. In a way, it freed us from the physical limitations of geography and paper, letting our minds wander, meet, and create things like LessWrong.
But now I believe some loosely coordinated actors threaten to change the Web for the worse. If allowed, they would turn it into a medium that restricts interaction and promotes passively consuming low quality information–like cable TV. I believe advertising and recommendation systems are driving this change.
The prevalence of ads has normalized them. Most people I've met have never asked "Where do ads come from?" If they did, they would discover it involves private data centers, a small army of software engineers, and enough hardware purchases to influence global markets. But for most, it's simply a part of reality, like electricity and supply chains.