Earlier quoted context omitted.
They're not giving manufacturers access to data in exchange for being integrated/pre-installed on the device; they're giving those manufacturers' apps access to data because they need that access in order to be able to present that data to the users who are accessing Facebook through those apps. It's not a quid pro quo, it's something that's fundamentally necessary for the apps in question to actually allow users to…
That might have been true in certain cases, but the article makes it clear there were other situations: >Facebook acknowledged that some partners did store users’ data — including friends’ data — on their own servers. A Facebook official said that regardless of where the data was kept, it was governed by strict agreements between the companies. Furthermore, why would they be putting an end to all these "partnerships"…
While I guess technically they could've use the normal API and only got the same information as Farmville or any random quiz could, this would have the result that - depending on what phones your friends used - you wouldn't be able to share information with all your friends without also sharing it with Farmville, Cambridge Analytica, and all the other shady Facebook platform apps that weren't held to the same privacy standards. That doesn't seem like a win to me, particularly since getting someone to click "yes" on a permissions dialog is a lot easier than creating a widely-used hardware platform and convincing them to use it.
(Of course, given just how many intrusive permissions it demands, getting everyone on the official Facebook app arguably isn't a great leap forward for privacy either.)