I managed to get sober on my own at age 25. My family didn't believe I had a problem. My mother said our "best conversations happen when you're drinking!" It took my moving far away from a family entrenched in the normalcy of alcohol, even though they weren't abusers, to hit bottom and help myself.
I grew up in a large midwestern German family. Every gathering involved gallons of beer. It was normal to rub whiskey on infants' gums when they were teething to soothe their pain. Kids grabbing a cup of beer at a wedding dance were ignored.
Early in my AA days I heard "normal is where you live." When most people are drinking or condone alcohol, as you say, that's normal. Distance gave me a new normal in many ways.
I'm sorry your son was swallowed by addiction. I appreciate how his Spirit still ripples out into the world through your words.