Everyone has a different way of believing they will be successful the way they are. You are right that going abroad can also increase your income but it cannot be said that you will be successful abroad. There are people who are successful in their own country and all have their own path to reach their dreams.
Yes exactly that not everyone is successful in abroad and there a person not always happy so interest also play a vital role in one's success. Sometimes people went to abroad but they don't get any job so instead of earning money they lost huge sum of money.
I think if a person has job in his own country then there is no need of going abroad because in own county there is a prosperous life with family which a man cannot spend abroad.