Another aspect is the cost and risk to the company if it ships defects to production (assuming it actually has customers, has largely de-risked product-market f

Another aspect is the cost and risk to the company if it ships defects to production (assuming it actually has customers, has largely de-risked product-market fit, etc). Suppose a company is in the hardware business and locks its cash into building and shipping a run of their v1 consumer product, then discovers after shipping there's a defect in the entire manufacturing run that means the product needs to be recalled and repaired. That's likely sufficient to bankrupt a young company that doesn't have revenue flowing in from other products or lines of business. You'd want to be doing a lot more QA than merely unit testing.