So our choices are that government has ubiquitous power to regulate commerce or none. Got it. I'm glad you've taken me under your wing to help me be more informed.
Here are reasonable things for government to regulate. Note what level of government is another matter, you referred to all matters. I am not saying the Feds have all these powers. I'm just talking about what's reasonable for "government" in general in my view. If I contract with someone and they don't honor the contract, I should have access to remedy. This would be civil courts. I should be able to get remedy if they misrepresent themselves in a material way. I'm also OK with requirements for disclosure of accurate information. For example, for things like privacy policies and discrimination policies, I oppose government forcing specific policies, but I don't have an issue with government requiring accurate disclosure of policies for people and businesses we deal with. Increasing informed choice is clearly increasing liberty, while restricting choices is clearly restricting liberty.
In the the Constitution BTW, the commerce clause was actually meant to empower the Federal government to expand trade, not restrict it. They didn't want States creating things like tariffs against other States. That the Feds use that clause for Federal dictatorial power to control and even restrict trade is a bastardization of it's intent, and that they do it for commerce within States is entirely an abomination.
This isn't about the federal government, or the commerce clause, unless your witch doctor is in another state.
This is about civics and the local and state common sense laws, regulations and rules that prevent chaos, swindling and catastrophe.
Let's replace your doctor with an electrician. You 'contract the services' of Joe Blow. He says he is an electrician and can rewire your house for 5 cents. No license, no credentials, no insurance.
So you 'contract the services' of Joe Blow to rewire your house, and it burns to the ground. Bad for you, but I live next door and my house catches fire and also burns to the ground. My family is trapped inside and doesn't make it out. BAD for everyone, not just YOU.
Now, by law, you CAN 'contract the services' of Joe Blow the electrician, but you will have to either break the law or lie. You can to have a government agency 'inspect' work that you do as a homeowner for safety and code compliance. But you have to lie.