What you’re describing here, sales people lying about capabilities and then failing to deliver, is something that maybe happens in complex business to business transactions, where the product is a set of services and products that defy “apples to apples” comparison.
Again, the sales and marketing are integral to the product. I don’t believe companies will survive if they practice outright fraud on their customers. This is not an easy problem. For the example, simpleminded approaches like forcing government to accept the lowest cost bid on complicated products has tremendous downside.
FWIW, managing people, organizations, setting up deals, marketing...these are “hard” skills. What makes them hard is that the parameters of the “problem space” are almost infinitely complex, the work product is ambiguous, and often the involves the focused cooperation of people, who are notoriously unpredictable.
Managed systems comprises of “soft components” is a very hard challenge.