you are kind of not allowed to evaluate worthiness on your own
I knew missionaries who wouldn't give a homeless person money, but would go into a shop and buy them food.
I knew a Christian friend who made the point you made; who are you to judge them? Does Jesus say give them what is yours, but only if you know they're not going to spend it on booze and drugs?
The reality is giving homeless people money rarely helps them. In a functioning western society, there is plenty of food and shelter in almost every city. Observing people in these situations shows just handing them money keeps them in an every present state of dependence. And with the people most likely to give being the ones who can't afford too, both the very poor and the very rich constantly leach off the well intentioned people in the middle.
Things are very complex.