hard works doesn't guarantee that you will become rich because if handworkers become rich then Labor will be the richest person all over the world. Sometimes lazy people get the reward because of knowledge and hard workers remains in the same state.
According to my opinion poor are more hard working than wealthy people. Other thing is that some people become successful because they have strong support from their parents and strong foundation of wealth from their ancestor which make them more wealthy.
In several cases that I have seen and experienced, many work hard, smart people, good people, have many relationships, but are not successful, trapped in a simple economic life, aka unable to become wealthy. Because in my opinion, hard work is not enough, you have to work smart too. Construction workers were much harder working, but they didn't get rich. There is a neighbor of mine who works part-time and is even able to build his house. Success is not because of hard work but the right place. The rest surrender to the destiny that God has given, because it turns out to be true, God's destiny is real.