Please check the App Store before you make obviously false and easily refutable assertions.

I wish you had posted the constructive form of reply, e.g.:

  Recently, Facebook added in-app purchases for things like X.

Because here I am still wondering what the hell X could possibly be.

Hmm, looks like a recent feature. I doubt it is particularly large.

> I doubt it is particularly large.

Facebook is currently 43 in the list of the top grossing apps. I'm still running iTunes 12.6 which shows these lists.

Ok, so Facebook is the 43 top grossing app. What exactly do you want them to do? Single them out and not allow them to use IAPs?