- I don't see the sets of costs argument - any price is made up of infinite sub-costs. You buy a carton of milk, it came from a distributor who bought it from a wholesaler, who got it from a carton plant and so on and so forth. At each step of the way someone verified the quality to ensure reputation. In a vertical corp quality control can be difficult.
- The opposite - easier to launch new companies. This is already how it is in places like Europe. No problem to sign 'distribution' deals, and no problem in seeking 'distributors' if you have the content. What's more a ton of other types of incentives make it easier to start new efforts.
I don't think you understand that mostly, this is how it all already works, by itself. That's the whole point of a 'free market'. Until Amazon rolls into town and starts buying everybody up and integrating it all into something else.
Forcing this would also have many downsides:
- if you make content that others don't want to distribute, are you not allowed to distribute it yourself? Freedom to publish whatever you want feels very valuable for society, IMHO.
- costs for consumers might rise because you now have two sets of costs priced in, instead of one set of costs.
- It's harder to launch new companies. If content providers don't want to work with you as a distributor when you're small, it's hard to get off the ground. If distributors don't want to work with you because your content is unproven, it's hard to get off the ground. Etc.