I think there is a fundamental misunderstanding about both evolution and markets, which is that either one "optimizes" something. Neither needs to create a perfect outcome. An organism doesn't have to be the best, most efficient possible at getting food, it only has to be good enough to survive long enough to reproduce. A cheetah does not need to be the fastest cheetah on the plains to survive, it only has to be faster than the slowest antelope. A company does not need to make a perfect product, it only has to be just good enough to turn a profit, any profit, in order to survive.

Once you realize this everything starts to make sense. Why can accountant have errors? Because they aren't bad enough to lose customers. Why can a product be made shoddily? Because it isn't quite shoddy enough that people stop buying it. Indeed, the most optimal thing for a company, profit-wise, is to be just as shitty as possible without going out of business. Any additional resources spent on increasing quality that is not demanded by the market are, in a sense, wasted.

This hurts from an engineering perspective because we want to make things that are good, but too often customers don't actually care about how good it is, just that it is cheap and just barely good enough to be worth purchasing.