You dont need deeper understanding of knowledge for everything. Ask Grandma whether she needs a chemical engineering degree to bake apple pie.

Then there is the Theory of Bounded Rationality which tells us expertise may exist but resources, time, energy, info, attention etc etc may not therefore bounds and limits of expertise alone must be recognized and solutions reached are satisficable rather than optimal. Aiming for optima when other factors havent been sorted just creates new problems.

> Ask Grandma whether she needs a chemical engineering degree to bake apple pie.

Grandma doesn't bake with "common sense", she is using the specialized knowledge of cooking & baking.

grandma's baking knowledge isn't common sense but expertise.

> You dont need deeper understanding of knowledge for everything. Ask Grandma whether she needs a chemical engineering degree to bake apple pie.

You've clearly never baked before. Baking is a chemical science. You have to adjust temperatures for your freaking elevation relative to sea level. Granted some recipes are pretty forgiving, sure, but far from all, and some are downright merciless in terms of complexity and effort required.

Even people who do it constantly have items that just don't turn out because it's legitimately hard shit.