If it were just about building and doing things in a social vacuum, and you can accept the risks of what you're doing without becoming paralyzed, there should be no real downside to having a completely realistic feeling for your own limits.
Here is the problem. In our business culture, if you are pitching to sell products, get funding or get hired, then you can't export the products of your realistic introspection. This is not effective. No one wants to hear it. And you will be despised: if you say tepid things about yourself, people will imagine even worse about you, and your competitors will easily make use of this. So whether you are delusional about yourself or not, you have to export a delusionally rosy picture of who you are and what you are doing.
If we want to stop incentivizing this, we can. But we don't.
I believe this is why artists tend to be more self-critical. They aren't making money(mostly) and so they're relatively free to consciously acknowledge their limits. The boundaries, when they're encountered, tend to come from social forces rather than market forces.
Similarly, a recurring phenomenon of financially successful artists is that they discard their old perspective and make work without the inspiration that powered their breakthrough.
Here is the problem. In our business culture, if you are pitching to sell products, get funding or get hired, then you can't export the products of your realistic introspection. This is not effective. No one wants to hear it. And you will be despised: if you say tepid things about yourself, people will imagine even worse about you, and your competitors will easily make use of this. So whether you are delusional about yourself or not, you have to export a delusionally rosy picture of who you are and what you are doing.
If we want to stop incentivizing this, we can. But we don't.