I think the idea is that a UBI would provide only enough money for subsistence, and the human drive for greater wealth and status would continue unabated. Status and meaning are certainly important, and people would continue to seek those out.

It's possible that many more people would want to become entrepreneurs, given that there would be a social safety net if they failed. Right now, most entrepreneurs come from an upper middle-class background, often with financial assistance and cushioning from their parents.