I've learned.

He may be interested to learn about the problem/disease. I suggest he learn from James Milam.

Under the Influence: A Guide to the Myths and Realities of Alcoholism Mass Market Paperback – July 1, 1984
by James Robert Milam (Author), Katherine Ketcham (Author)

I have let them go as friends because of it. Others I have helped like you want to.
Showing up like he did you should help him but not hire him. IMO.

In my role as a regional manager I sent many people to rehabilitation for drugs, mostly alcohol. All except one came out of rehab a new person with good attitude and much better employee. But over time, usually 6 months to a year they had fallen back into having issues. In the case of drugs vs alcohol it went mostly undetected by their behavior on the job. The primary issue was attendance and dependability. They would just almost disappear for 2-3 days, their manager unable to contact them, etc. Sadly the long term consequences for most was termination and in some cases even death. It is hard to see someone you have known for years fall into such an abyss.

The one things that is an absolute necessity, I think, is they have to stop associating with those with the same behavior. Addiction is not a easy problem to solve. Only the individual can stop the cycle - I think (not an expert).

As far as old friends - I also have a similar situation with two of my oldest friends. In one case I have known this friend for over 45 years. In the meantime he has been through 3 divorces, my wife doesn't like him coming around anymore and the dude is a total narcissist who is constantly blaming others for his problems. He usually calls me when he is drunk and it actually ruins my evening because there is no conversation just blab blab blab, blab. I can't get a word in edgewise and it never fails at the end of our conversation he will always bring up religion. I listen for a while and then just try to politely hang up. But it makes me feel bad and I wish he had never called.

Seems very fair to me.
Great to help, but there has to be limits. That sounds fair.
I went through rehab 30 years ago. I was self medicating for a pain I didn’t understand. A great psychiatrist took me under his wing and only then did all make sense to me.
Good luck.

He was in denial. Some friends offered him a job but he failed the drug test. He finally agreed to go to rehab. Cost us alot of money but was worth it. He Has been clean for 10 years with a steady job and recently married. His addiction impacted his daughter more than anyone and they still have aa rocky relationship. Your friend needs to go to rehab and go thru the AA and NA streps. Don't be an enabler any longer . He will thank you when he's living a normal life again.

A good friend does interventions for a living. (His partner did mine a bunch of years ago). He's a great guy and might be worth talking to. If you need contact info, DM me and I'll be happy to share.

He needs to talk to another alcoholic. We know the details like nobody else. We are the ones who have lived the life of a pass out drunk. We've been forced into rehab by bosses, judges, spouses and children. There is nobody who will be more honest, believable and approachable than one of us who have lived through it.

If he doesn't like what we have to say, we'll happily refund all his misery.