Another note is that if you're irreplaceable and your (potential) customers or your investors know this, your company is less valuable. If they don't know abou

Another note is that if you're irreplaceable and your (potential) customers or your investors know this, your company is less valuable. If they don't know about the problem, it's still less valuable but you may be able to pretend it's more stable than it is. Having a non-unity bus factor is not only good for your sanity (you can take breaks, or quit) but also good financially. And even if you continue working, increased documentation and sharing domain knowledge can only make the day-to-day go more smoothly.