Question involving pulleys?

So. If pulleys reduce the amount of work needed...why hasn't someone just simply put a bunch of them in something like a handheld tube with TONS of pulleys and a durable, malleable, string (some sort of medal) and sold it as something like a superlifter? Seems like you can just put like 30 pulleys in a tube and thread the string through it, reducing the input force by 30. This is probably a stupid question. Sorry if it is...