Hello friend. The thin to remember about alcoholism which I'd say 15 to 20 beers daily counts for is that alcoholism is progressive. It can become even worse and will if he continues most likely. That he can still function now and have a job is a blessing but likely won't continue long term. That you already see an issue while engaged and aren't satisfied with the situation is hard. I believe that sometimes it is in our best interest to walk away. I can't advise you to do that but will tell you that I did. My significant other had a drinking problem. I loved him dearly but left him. Because I had the vision of a peaceful life without addiction as a part of it. I know that someone with addiction to whatever often have a lifetime battle and that the drug of choice is more important than me to them. It's a hard, HARD life. It's your choice if you want to walk this walk and risk what the future usually holds by tethering yourself to an alcoholic.
You won't be alone if you choose to stay. Many women (men too) choose to. But make no doubt that they often feel isolated and I believe need a lot of support. Al Anon is a group that offers such support. Let them be with their addiction while you love them but setting boundaries becomes part of it as well.
It's really hard because I hear you saying he is a good guy. And I fully believe you. But he also has a disease that could greatly impact your ability to have a happy life in the future. And children that grow up in an alcoholic home often have irreparable damage. Not only are they at greater risk of mental health disorders but they also have a much greater risk of continuing the cycle of developing addiction themself or getting into a relationship with an addict.
What does he say when you ask him about his drinking?