Courage in the face of variance
Startups have high variance: the top few % reap most of the rewards.
The same is true for artists of all kind, and to a lesser extent, software engineers: some Waymo engineers earn 100x the salary of the lowest-paid programmers.
Risk is usually taken to be bad. But it might not be if you can influence the outcome. If you think -- possibly irrationally -- that you could be in the top 1%, then it's perfectly reasonable to enter a field like that.
In fact, attempting to start a startup, or become a musician, or write books for a living, implies strong self-belief. It betrays an internal belief of yours: "maybe I could be one of the best".
But it's hard. You suffer at the hands of the internal critic. There's a conflict between your current level, and your belief that you could become great. A conflict that's in your mind every day.
Which is why I have immense respect for anyone that tries.