This isn't "I'm smart and rules don't apply". Smartness alone doesn't help.

But, to put it this way, if rationality training doesn't help improve your startup's odds of success, then there's something wrong with the rationality training.

To be more precise, in my experience, a lot of startup failure is due to downright stupidity, or just ignoring the obvious.

Also, anecdotally, running a startup has been the absolute best on-the-job rationality training I've ever had.

Shockingly, successful entrepreneurs I've worked with score high on my rationality test, which consists of how often they say things that are uncontested red flags, and how well-reasoned their suggested courses of action are. In particular, one of our investors is the closest approximation to a bayesian superintelligence I've ever met. I can feed him data & news from the past week, and almost hear the weighting of various outcomes shift in his predictions and recommendations.

In short,

1. Rationalists are more likely to think better, avoid obvious errors.
2. Thinking better improves chances of startup success
3. Rationalists have better chances of startup success.

I do understand this sounds self-serving, but I also try to avoid the sin of underconfidence. In my experience, quality of thinking between rationalists and the average person tends to be similar to quality of conversation here versus on YouTube. The problem is when rationalists bite off more than they can chew in terms of goals, but that's a separate problem.