I once created a Facebook account to test something and for some reason it decided I was some sort of gambling addict (that e-mail was registered on a legitimate gambling website and I guess they leaked it) and the "people you may know" was full of fake accounts all related to some kind of scummy mobile casino game (I guess the game requires login with FB or maybe gives new people free tokens so they just register tons of fake accounts?).
I've spent a good 20 minutes reporting every single one of them (up to actually hitting the rate limit on the report endpoint) and not only did the algorithm not take the hint that maybe it wasn't a good idea to recommend me more accounts out of that category but their support didn't deem the majority of them as violating the community guidelines despite them being obviously fake (and I couldn't notice any difference between those that were deemed as violating their guidelines and those that don't).