Pursuing knowledge for knowledge's sake always results in improvement down the line, even if it's impossible to predict when and how.
Do you think Benjamin Franklin expected a payoff from the experiments that led to the discovery of electricity? Or Newton researching gravity? Much of our knowledge about the universe comes from researchers picking at a topic just for the hell of it.
> I would rather someone of the intellectual calibre you describe work on problems more relevant to improving the world.
Impressive amount of entitlement here. Nobody owes you anything, and people are free to do anything they want. Not everyone wants to be a hero or great inventor, even if they have the skill for it. Nor is it some universal moral obligation for skilled people to spend their lives producing something profitable or beneficial to society.
Do you have hobbies? If so, you should feel bad because you're wasting your talents on useless unprofitable activities. Better go out and solve the world's problems.