You don't generally have to check if your food is made with lead or carcinogens though right? And if inspections aren't compulsory some people are going to get lead poisoning before word gets around, or get cancer decades later and never know. Better to have someone qualified to check it before it gets to the shelves. Granted I'm using lead as a hyperbolic example, but I'm sure you get the point I'm trying to make.
Why are free markets better at dealing with partial knowledge?
Why are free markets better at dealing with partial knowledge?