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.
I was doing analysis at of how things were in the 90s and now and the things that gives value now and then is actually different, labor maybe wealth to some people, brains might be wealth might be for other so everything is just different for everyone and I feel like wealth is no longer by labor, just that you if you don't work you won't eat, we know that the effort is good and even if we are trying to be smart we still effort even in our consistency, how it is built is also very important because everything will start from the mind and how prepared you are towards building the future.
We don't need to separate between hard work and smart work, these two things as you mentioned about energy with past dogma in effort and smart in today's thinking about business, honestly these two things are very related and if you combine both to get wealth it will be much faster, because if separated, smart alone is not enough to build wealth and hard work with energy alone is not enough to build wealth, therefore it must be combined, we must work hard and work smart, I often see an Elon Musk who only sleeps for a short time and even sleeps in his office to ensure his business is successful.
Energy and brain are tools that we can use to build wealth.