Poverty will always exist because it is usually a relative measure. Being poor in the U.S. and being poor in Kenya are two different things. That is sort of a "well duh," but everywhere in between the meaning of poverty changes continuously. We could reach a point in a distant where everyone in America owned their own home, owned two cars, put their kids through college without loans, and paid for their own healthcare; and this would be considered "barely getting by" because the family doesn't have three cars or a second house or whatever.
The burden of proof is on you here. The fact is that humans are not perfect and will never make perfect decisions. One can still gain a very sizable advantage over his or her peers while still making less then perfect choices. Its the major screw ups in life, such as having a kid out of wedlock, dropping out, not obtaining any marketable skills (not just from college) etc. that set people back a long way. Also if everyone made perfect decisions, then everyone would be perfectly productive and yes we would get rid of poverty quite extremely quickly. That is clearly never going to be the case however, but I have no doubt that if we at least improved the demographics of good decisions vs. bad decisions it would lead us to be better off. If we had less people who have a fatherless kid as a teenager, we would be better off because we would have less people being structurally held back from any sort of upward mobility.
Were there poor people before welfare? Yes. Some people struggled. But it is you who said we should look at statistics rather then personal stories and I would point out that we saw a vastly higher amount of wage growth when we did not have welfare and disability insurance than we have in the last 50 or something years when we did.
I hope you did read the article behind the OP, because what it is talking about is a very dangerous prescient.