How can anybody judge who is a "useless person"? It is not possible to know enough about everything someone has ever done, and every influence in the world that they have ever had, in order to make this judgement. Only with perfect knowledge of another person could such a judgement be made. None of us humans has that.
Useful education is good, of course. Does it matter if it is accompanied by a document? A document is very useful for some things. It can help you get a position. A document can prove to others that you have managed to pass and so will likely know what you are talking about in regards to your own area of expertise. Once a very well self-educated person I was close to told me he had always been in awe of those with high degrees. He finally became independently wealthy through his own efforts, and eventually found himself travelling with doctors, lawyers and many other kinds of highly educated people. He lost his humbleness before them when he found that most often they only knew their own specialties well, and were remarkably ignorant about other things. He had a broad and deep self education so he was thoughtful and well-informed about almost any subject that could come up. Should we call him a "useless person" because he was self-educated? How stupid!
Someone could have no education at all, and still not be a useless person. That person might have done only one kindly or somehow valuable thing in their whole life, but it could have had more widespread influence than they or we could ever know. It is not even possible to know your own sphere of influence. The words "useless person" are terrible and arrogant words to apply to any soul.
Only God really knows each of us. I suspect that after our life is over and our record has finally finished here in this world we are given the understanding to judge ourselves. This could be what makes for us a future after death of "heaven" or a "hell." Even then, if there is a sincere asking for forgiveness and help God may help that soul to improve.
We must be careful of what we do. We could be committing terrible errors with such words. Then we will be the ones who will learn to our dismay the things we have caused, and how widespread the damage became, when we come to a world where everything is made plain. Right now we could be creating our own heaven or our own hell, act by little act, and word by little word, all piled one upon the other.
Maryk