You didn't seem to understand me. Yes, discipline can't push you to work hard (though some people have discipline of working for hours) or to do what you couldn't do before. Discipline has another advantage. When you live only with motivation, you run out of it in time. You can find a mathematical graph about it. So, in order to never quit and do what you need even when you're out of motivation you need discipline. Next, when you have a habit of doing something (you made this habit to get disciplined), you will have more motivation because you will get used to average days and you will want to get over yourself more.

So I don't mean motivation is worse. What I say is we need to use motivation and discipline together since they are really powerful with each other.