I drank a lot, a lot of times. Bad things happened, sometimes immediately, sometimes gradually.
That being the case, my two options were: moderate or stop.
Firstly, I hated moderating and could rarely pull it off.
Secondly, I could stop for a bit, but always started again, and my resolve to stop seemed to come and go, even though the evidence shouted clearly to everyone including me I should stop.
Put these together: drink too much, can't moderate, can't stop, and you have alcoholism.
What is alcoholism? A condition that is progressive (gets worse), fatal (will take many years off my life), and incurable (I will always have it).
What's the solution? Physical abstinence plus a programme of action that rewires me and keeps me safe in a fellowship of people. AA does that. Maybe there are other solutions.
I am super active in AA but have a successful, interesting life, 27 years later.