Companies are using every scrap of data they can get their hands on to take more of our money and they want more. The government is buying up data they can't legally collect directly. It's pretty likely that you've already experienced real world consequences of the data taken from your online activities. (https://epic.org/issues/consumer-privacy/data-brokers/)
They tell us that all the tracking we're subjected to is just about ads, but the data being collected is used all over the place offline. What we really need is privacy regulation with real teeth, but that's probably not going to happen any time soon because it's making companies tons of money. There's a multi-billion dollar a year industry around the buying and selling of the our data for a reason.