What I can say is that hard work can put food on your table but it is not enough to make you rich, to be rich you have to think beyond working hard because if you think smart and take advantage of the right opportunities you can earn in hours what your hard work cannot earn in one year. Many successful people don't struggle to make money with their physical strength, they find ways to own a business and let others do the hard work while they direct and manage the workers, if the business grows they will delegate management to qualified people and direct them. If you continue to depend on what your manual hardwork can pay you then it would be difficult for you to succeed beyond what your strength can carry but with smart strategies on how to make multiplied income you would think of how to partner and hire others so that you can generate more income than what you alone can work to achieve, that is how wealth is built.
I agree with your opinion that hard work has limited benefits especially since it is directly related to the number of hours one can work in a day.
Working hard can increase income but there is a fixed number of hours in a day. This is their skills networking on a ship, and also the ability to recognise the available opportunities around us plays an important role. Another thing is we cannot say that these successful people let other people do hard work for them at the start; they do a lot of hard work they still carry race can responsibilities of running a business. Selling their time and energy, they sell their valuable assets and build systems. Hard work helps to build a business through experience, skills and smart decisions help to use those skills efficiently and also to create more opportunities in order to grow.