Not all hardworking people are successful, but all successful people are hardworking. Success is not guaranteed, it has an element of randomness. Attempting to be successful involves risk, and "survivorship bias" should be accounted as part of that risk. But still success is not entirely random, because only playing video games or watching TV will not result in it.

It's not that you should think that consistent engineering effort alone will have any payoff, it's that you should think consistent engineering effort might have any payoff.