'If you're not paying for it, you're the product'—actually that's not quite right. You and I aren't the product, our attention is, and that's a crucial distinction.
The internet has turned us into dairy cattle and hens; our attention is sold like milk and eggs. Most of us are raised on industrial server farms. We have 'access' to the outdoors—that's the internet outside of Facebook, YouTube, and Twitter—but the farmers know that few of us will ever go there. Our feed is an endless stream of electronic news; it keeps us fat and our attention flowing.
If you feed cows a diet of corn and soy which their stomachs were never designed to digest, they get sick. If you feed people a diet of novelty and outrage which evolution never prepared their minds for, they also get sick.
Facebook, Twitter, and Google don't care whether your feed is good for you; they don't care whether your mind was ever designed to consume this much novelty; they don't care whether their feed creates bloated fat cattle or chickens that can barely stand on their own legs; just as long as you keep producing that sweet milk of attention that they can sell to advertisers.
And sure, over time, if you keep consuming a feed full of outrage, click bait, and ideological bubblegum, the milk you produce won't be very good. But people have short memories, and most of us don't even remember what real attention tastes like anymore.