Well definitely not that they don’t exist, just that maybe they don’t exist if there’s a company that acts as a middleman between the customer and the contractor.
The issue is where the middleman determines all of the terms for both the contractor and the end-customer.
If I as a customer can reach out directly to a bunch of contractors independently, then that’s a fair free market, and the contractors can compete for my business or not accept it at all if they don’t like the terms, without harming any of their other customer relationships.
But if I as a customer can only reach out to a middleman, and that middleman decides who works for me. And the contractor also doesn’t get to pick their individual customers. Then it’s clearly not a fair free market at all.
If there were a company called SanFranciscoHVAC and I reached out to them to fix my heater. They send someone out to fix it. But I don’t get to pick who comes to work on my house, and they don’t get to pick who their customers are. And they can’t refuse a job or else SFHVAC stop giving them jobs. Can you really call them contractors?