what good does it do の意味は？

You should put your health before your job. I know your work is important to you and you need a lot of money to buy a house of your own. But what good does it do if you are not healthy and you can't enjoy life with your family? You should really take my advice.
what good does it do の部分だけが分かりません。
どなたか教えていただけないでしょうか？