Curing cancer would be infinitely more profitable than yet another crypto exchange. But humans are greedy. They won't wait for the big payday when a metaphorical marshmallow is dangling in front of them. Even holding out for the rewards of a crypto exchange is more than most people can handle. Most people will indulge in the not-so-tasty treat in front of them as soon as someone offers them a mediocre job.
> Governments exists to regulate society and set rewards and punishments
That may be true of an authoritarian regime, but under democracy, as I imagine most of us here are, government does not regulate society. It regulates individuals who try go against society. Society defines expectations, government cleans up those who refuse to comply. If the general public interest turns one way government can step in to ensure that the remaining people are brought into line, but a (democratic) government will not lead the charge.