Why are people like this?

So @CapitalCitySaint brought up the "Apple Cider Vinegar" Netflix series about scammer Belle Gibson from Australia. And I mentioned having missed the ABC Scamanda doc which is about Amanda Riley. And then on Peacock there's "Anatomy of Lies" which is about Elisabeth Finch who is a television writer known for True Blood and Grey's Anatomy. What do these 3 ladies have in common? They all very elaborately -- I mean like complete with faked pictures of being in hospital beds and medical reports and the like -- claimed to have cancer and never did.

I think they all insist they never MEANT to scam anyone, it just sort of happened. Now, no one here is really talking about these cases -- or any others that might be out there -- but I ask you: Why are people like this?
Won't get scammed if you never expose yourself to them.