I haven't seen anyone here belittle Phil's ability to bilk money from kids, it's more of some people puzzled by how Phil's able to draw them in and find replacements for people who grow up or had their moms find out about their stolen credit cards.
On a tangential note, I guess it depends on how you define success. If success for you means being able to amass money, then sure, Phil is a success. Personally, though, having that much money means jack if you can't put it to good use. I mean, you can't literally buy happiness, but having boatloads of money means having the ability to buy things and experiences that does make you happy. And for all the money Phil gets (and with little effort, to boot), he doesn't seem able to find something to buy that truly makes him happy. He looks miserable and visibly aged most times when he streams. That's not a happy camper, even with the thousands he makes.