For starters, it's not just browsing history but all of your activity on pages or in apps that use Facebook's spywa..."ads". This includes activity times, connections to other users, and even proximity to places or other people (Bluetooth beacons etc). This is all on top of the voluntary PII you might have fed directly into a Facebook profile or the shadow profile they
helpfully created for you when your friend uploaded their contacts into Facebook.
There's zero oversight of how that data is used or who it's sold to and what those buyers do with it. We've already seen a number of cases where this harvested data was sold to unscrupulous or outright criminal concerns.
So it's not just Facebook using browsing history to sell you boxes of Tide. They're selling dossiers on you to groups literally trying to gaslight and manipulate you, to subconsciously influence you to do things, or to just make you generally feel like shit. Facebook exacerbates this behavior by "advertisers" by using your dossier to stick you in a filter bubble while at the same time showing you content that maximizes "engagement" and nothing else.
The dog wagging and gaslighting are not common knowledge or well understood by most people. Neither are the shadow profiles or the access of data by any organization that drove a dump truck full of money to Menlo Park. They're worse than the old school information brokers and credit reporting agencies because they feed all of your behavior into their graphs rather than just transaction history or public data.