You are over-simplifying. Almost all of the metrics Facebook will feed you when you setup an account are on a view-through attribution basis. Yes, there will be some clicks, but if you attribute revenue from Facebook by clicks only, it will look terrible. This is an old problem for anyone that has spent time with display ad platforms. So, you install a facebook pixel on your checkout, and if the person making a purchase saw your ad on Facebook, Facebook's reporting console will take credit for that. Thats view-through attribution and it highly overstates the credit Facebook should receive for making the sale, but there's not much you can do to measure it otherwise. So what do you do? The answer is, you setup a holdout test. Facebook has a black-box solution for helping with this, but it is a huge conflict of interest to let Facebook handle your test. The thing to do then is set up the test on your own platform. That is a massive undertaking, and any business that doesn't have a significantly sized engineering and analytic team doesn't stand a chance.

So yea, people look at things like reach, and view through conversions, and it would be very hard not too or they might not have the means to do something more sophisticated. Fake accounts undeniably puff of numbers for these people, and they should be taken to court for not giving a shit about that fact.