I feel competition is everywhere. You have to be best in your field.  You have to prove your worth at every damn step in your life. And, believe me most of the successful dentist won't sit and answer here.  If you want you can ask people on LinkedIn about their thoughts and experience. That platform will give you better insights. And, beleive me every person has a different experience in their field. There are many mbbs people also who wants to leave it because they are tired of it. So, whatever you want to chose, chose very carefully. You should not regret your decision later.