The majority of US states ban direct car sales from OEMs to consumers. This is what I'm talking about. Dealerships helped write laws that mandate their existence in this country. This has resulted in them repeatedly price fixing, which is legal because of their lobbying, and as a result consumers often pay more for cars than they need to. Over the last few years multiple OEMs have started terminating their dealership agreements because of this. Ford made headlines cuz of it.
This isn't my opinion, it's pretty easy to google. This is a well known issue that multiple states have changed their laws on. Many more are in the process of repealing these laws because they hurt consumers. This isn't a free market, it's literally the opposite. lol. Tesla made a huge stink about this back in the day and still has to work through loopholes in a bunch of states. The dealership requirements hurt small car manufacturers which again hurts consumers.
And no, grocery stores are not allowed to charge "whatever they want". There are price fixing laws. Grocery stores were investigated repeatedly during the pandemic for price fixing. lol