People being defrauded, injured, poisoned, and dying must be much more efficient. That's the reality that drove the formation of these agencies.
I'm sure an inability to trust the safety, quality, and accuracy of the things one buys wouldn't have any negative effect at all on a market.
The illustrious and unbesmirched track record of the worlds major auditing, accountancy, and credit firms has demonstrated beyond doubt that private enterprise can truly be trusted to handle these matters in a manner that puts society's needs at the forefront.
Since we're already laughing, I propose we go further! Privatising the military would unleash the inherent good and efficiency only found within corporations. A free market of privately held armies, competing against one another for the benefit of society. Federal taxes would drop drastically, what could go wrong?