I commonly hear families say, "you have to get sober for yourself", but I disagree. I say , any reason is a good reason to get sober!
However, most people find that they want to stay sober because their life gets so much better. One especially important thing that improves is the person's ability to be present in their life.
In active addiction, everything else in life is just stuff you have to do before you can get your substance. Addiction consumes your thoughts too much, you are eventually just going through the motions of your life.