It's an arms race, and the problem is that there are two groups of "bad guys." One group of "bad guys" are the ones who want to track what you're doing even af

It's an arms race, and the problem is that there are two groups of "bad guys." One group of "bad guys" are the ones who want to track what you're doing even after you've cleared your cookies or track you across different domains or different apps. I would argue that this group is the smaller group, but browsers have been taking actions to make their jobs harder, including the "Facebook fence" that Firefox implemented. There's a second group, which is the cybercriminals (or maybe just grey-market). Think Russian bot farms and purchase fraud bots, but also the guys who sell clicks and followers and rankings, and the ticketmaster bots and black friday bots and such. Those guys do their business by creating thousands or millions of fake accounts, and then funneling their transactions through them. They generally use scripts and cloud farms (sometimes even physical device farms). So app makers and websites need a way to detect when they're being attacked by one of those guys, and the way they do it, is more and more, through fingerprinting. So every step browser and OS makers take to make the first group of "bad guys" jobs harder also makes the second group of "bad guys" jobs easier, because it makes it easier for them to pretend to be legitimate users.