People shouldn't necessarily work on what they want, they should work on what others value (whether that's a want or a need). Obviously it good when you can find an overlap between the two, but there's really a sharp limit to the number of professional masturbators, bong-hitters, and video-game players needed in an community.
Those who invented modern science actually spent much of their time working on projects for their patrons, just as artists did at the time. It's every adults duty, at least until retirement, to discover something that others value enough to pay for, that they won't hate doing, and get trained as needed to do that, then make that contribution to the community.
There's just no other way for the goods and services we all want and need to spring into existence. Not tax structure causes food to grow, nor houses to be constructed, nor the trash to be hauled. People doing what others value so that they can have the things they value makes all that happen.