Working smart AND working hard both do not guarantee anything either. Nothing in the world could guarantee you money or success, there is nothing that is like a template where you do it and you get money, tis just not possible.
You just do it, and hope that it works and if you are right then you could make money and if you are wrong then you won't. It's a bit of luck as well, some dude making a video going viral doesn't mean that you will go viral too, nor does it mean all of his videos would.
Exactly. Working smart or working hard does not guarantee anything. Success is not something that can be easily achieved through hard work or intelligence alone. That's why many people work hard their whole lives and still do not get rich, and many people are very intelligent but do not succeed.
However, no one will succeed or become wealthy without hard work and intelligent thinking. Therefore, although there are no guarantees, if we want to succeed, we need to work hard and smart.