Both of them are indeducated people who haven't read a book in the last decade at least, who have no culture, who have no thirst of knowledge of any kind, but who - somehow - know everything about everything.
They live jailed in their own homes with pets they abuse, and partners they don't love, manipulate and abuse with the sole purpose of appearing human. They both, as soon as they are done with said partner, get rid of them and make videos crying because they were evil, used them, never loved them like they deserve. It has also to be said their relationships appear to be a cover up for their actual sexuality (Onision has spent the last ten years drooling after Shane Dawson, not to mention constantly reminding him that they once kissed; Amber is, at least in my opinion, a lesbian out of convenience, because she knows how to manipulate fragile women better).
They have no friends but passing people they put in their videos because, again, people in their thirties are supposed to have friends. Their families despise them to the point of having little to no contact, and their encounters with their siblings appear to be uncomfortable and incredibly forced.
The way they reached success is pretty much the same: they both used dumb internet phenomenons and are now still dragging them by the hair, hoping to get enough views to get a juicy paycheck and keep their luxurious spending habits, no matter how many stupid things they have to do or how many people they have to exploit to get it.
Oh, and let's not forget that Amber wants to be a writur, and Onision published two books that hilariously flopped because of how terrible they were.