Labour for me is human productive effort towards achieving set target.To answer the question, labour may be wealth, in the sense that when others labour while you fold your harms and watch from where will the wealth come from? Wealth creation cannot be separated from human effort both mental and physical.
You know one could also labour so hard yet nothing to show for it. it's not just about working hard or labour it has to do with several things hence success or wealth can be created.
In my place their are set of people know for all the hard work, they can work so hard do everything but they still remain the lowest in wealth creation, in as much wealth is concern you must put lots of things in consideration to create the wealth you desire.
Maybe luck is a little involved there so that there are some people who have worked hard but did not get the results as expected, but I think when you have tried to step then at least you will get an experience that will be a lesson when for example your hard work does not achieve success. Like a group of people in your area that you have mentioned who have worked hard but are still in a low situation in life, but I think I will not conclude everything too early, remember that there is no measure of the length of time a person must go through, and that means that maybe the group of people you mentioned are those who are still in the process of achieving something big and proud, because after all hard work is one of the keys to success.
Precisely, luck is relative and it may work for or against someone depending on the aspect under consideration; however, the input, effort and hard work has a direct positive relationship with the accomplishment of goals. Even when one tries so hard and gets no results he or she gets other things like experience from the efforts put in. Perhaps it could turn into a learning experience which steering changes for the better next time within the strategies and the approaches being used. In many situations, consistency and perseverance are the main factors which may define success, even if there may be years of waiting for the outcome.
One must also note that everyone has his/her own success story and the period to success differs from one individual to another. While looking at the group of people you named, they may not necessarily get the results they expected, this means that their efforts were not wasted. This process could be a step forward to the achievement process. Sometimes success is not easy and that brings in a very important factor which is tenacity in the face of challenge.