Money? The challenge? Opportunity to do something new/different? Team? Impact? Personal connection to the industry/space/product?
I'm curious to hear different perspectives on what draws people to work on a new startup idea, particularly at an early/unproven stage.
For me the appeal is being able to build things from scratch, and make big decisions before the stakes are too high. It also opens the possibility of growing into a larger role than if you join a big company.