I had to ask the same about my brother, twice.
I am what my wife and co-workers refer to as a functioning alcoholic. Whatever I am I have been so for a decade.
At any rate, I took him in nearly 15 years ago (I was in my early 30s he in his mid 20s). It got to the point that when Shoprite had a sale where canned food was cheap I would give him $20 and if he came home with ANY food we saw that as a positive and used it as an opportunity to provide positive attention.
Regardless of our support emotional, financial, roof, etc. he spiraled mightily.
My wife at the time and I never stopped caring but we cut him loose. He had to find his own way...which resulted in jail and drugs and more jail. Which for a milquetoast family was a big departure from what cousins and others were doing.
Like others hare have stated... he had to determine his own stopping point.
Yes he is someone who will always struggle with addiction with drugs and alcohol...that said, he has been clean for close to five years. Remarried, has a family and from every indication is finding his way.
He embraces religion more than support groups but does both when he needs.
Expressing "good luck" is shitty because I recall how awful it felt to feel as if I was turning my back on my little brother.
He understands and I like to think we are as close as we were when we were kids.