They are around 7 or 8 million in number, so don't take care of the world's needs. Their main focus is on preaching the Kingdom news earth wide. Matthew 24:14.
In fact, when Jesus was on earth, he preached far more than he performed miracles of feeding people with loaves of bread and fish.
He, in fact said: "You will always have the poor with you."
You may not recognize the preaching as being valuable but that is because you don't share their beliefs. Whether their preaching is valid is subjective.
But no one can argue the fact, that many who become JWs better their own lives. Some give up drugs, drinking, cigarettes, etc. Some who wouldn't work, improve in that respect too.
I remember a friend of my sister. He was a gambler, drinker, smoker, drug-user. He gambled away his rent money and then went to the Catholic church for assistance. They gave it to him and then asked if he needed anything else. They then proceeded to give him shampoo, toothpaste, etc.
If that man became a JW, he wouldn't have even needed to ask for money, because he would have given up those vices.
JWs actually do help out others though. Once I was short of money and another one gave me money when I went to a convention. I also helped out another lady financially.
There was a JW who had a health issue and we all got together and helped her financially. I have helped and been helped.
We help non-JWs too. I have given rides to homeless ladies and given stuff to homeless shelters and charities for abused women.
I know of JWs who shovel snow for neighbors.
We also provide disaster relief and not only to fellow JWs.