Good work calling out a real problem. There's a beautiful and powerful saying "Grass seems greener on the other side". People should remind themselves always. It will really give you a reality check.

There's one more issue, people tend to glorify their so called achievements as if their life is all perfect now. That's a big lie. These people do it to hide the flaws out of ego and want hide the illusion of their flawed achivement. All of the people you see who seem to be doing better than you, wait till you find out flaws in their life. You'll then find to that your life is okay as is.

Ofcourse that does not mean you do not strive to become better. You should always and gradually refine yourself, but the comparision should just be with your past self.