This is a tactic broadly used in AdWords in the past, and I assume that it's also used on FB too.
The above gets even worse when I tell my brother-in-law that he shouldn't bother with FB ads for his new pet food store, this other platform is a better value.
Thus it is long term to FB's advantage to make their numbers real. I can't say if they will or not, but it would be to their advantage.
As for click-fraud is pervasive in the online world. I don't think there's any major platform that doesn't have a fraud problem, and I can't realistically think of a solution that's not too much of a problem to work it out. Google is supposedly on top of it for more than a decade, but I haven't met a single person advertising on AdWords who doesn't think that they get fake traffic. I've even read reports that state that one third of global ad traffic is fraudulent.