You aren't happy with him "checking out" from your marriage for days each week.
Alcoholism is progressive--it will continue to increase and get worse untreated.
I am a recovered alcoholic, and that was true for me.
You need to trust your own feelings about this, not your friend or us.
Learn all you can about alcoholism, and realize this may be as good as it gets.
Are you ready for a lifetime of being in a three-party marriage?
You, him, and the booze?
I don't buy the "cultural norm" thing either.
You have one life--you aren't an aggregate of culture but an individual.
What do you want for yourself in this situation?
No rush to decide this but going with the flow may not be satisfying to your soul. . .