History shows us that merchants and service providers are constantly, constantly out to deceive and screw us. It's just a fact and it's why we have so many consumer protections.
The government is also not to be trusted, it's true, but at least we can vote them out.
Once in n years. And you don't really vote them out. You get the same parties and interests screwing you all over again.
You just don't see consumer protection as a service while it is - and it's monopolized by the government. If you had private consumer protection agencies financed directly, then the moment this agency starts screwing its customers, it's out of business, because people stop paying. Compare this to consumer protection via a government: you can't simply stop paying, you can't effectively influence how an agency works and you don't have a choice between various protection agencies that best suit your interests as a consumer.
Now tell me why should I ever choose government over a private market given this situation? In other words, can you convince me (and not force me to comply) that a government can protect my interests better?
What power does a private agency have? None. That's why you choose a government agency, so that when someone starts selling cheap crap to kids that's covered in toxic paint, it can be shut down.
The government is also not to be trusted, it's true, but at least we can vote them out.