It is not that difficult to try. In fact, many restaurants tried turning into grocery stores during COVID-19 shutdowns. Realistically, succeeding is going to be nigh impossible, though, as there is not much you can compete on. You are not going to be able to sell the product for less.

You are right that this is not bound by a regulatory barrier, but it is limited by the market barrier that was also spoken to in the previous comment.

https://news.ycombinator.com/item?id=37869309

Is it possible businesses are colluding resulting in increased profit margins? Obviously.

But we have publicly listed companies with public financials showing non material increases, or even decreases, in profit margin. Which means those businesses are just increasing prices to cover their own increasing cost of goods sold.

As the ostensible computer scientists in the room. Sitting back and not pointing out that there exist "monopoly pricing indirection mechanisms" implemented as businesses is really failing to do one's moral and ethical responsibility.

And yet the empirical evidence is not there due to nonexistent profit margins.

Because it is of course completely obvious that collusion among very large, very complex competing entities is a very easy proposition, you just need a magic algorithm to do it! /s