> I say there should be an explicit difference between "running a platform", and "selling on a platform", and never should the two meet.
Its a free market, you can do what you want as long as costumers like it. Valve makes its own games and the platform. There are other example where this is true.
Should SpaceX not be allowed to launch Starlink. Falcon 9 is a platform, and Starlink is selling the product that you get threw this platform. Maybe not a perfect example, but one could equally make a argument about that as well.
All of these things are pretty artificial opinion based market restrictions, and everybody want to create different rules based on different was to evaluate this question for every market business and so on.
So you would make totally different choices about what is a platform and what isn't. If my company has a product and then opens up the underlying API, is my product now illegal?
For me this is all nonsense, why not just have both the suppliers, consumers and everybody else involved make choices based on what they think is best. Why do you know better of how to define these terms and what evidence is there that when you force a separation it is better at 'raising all boats'. There is no evidence to prove that in the majority of cases.
In the example of Steam they lost many games because suppliers didn't want to deal with them. Microsoft SQL now runs on Linux because people didn't want to us Windows. In all of those cases, costumers and suppliers are perfectly capable at making those decisions for themselves and then the company has to make choice how adjust to this situation.
Why any of this is bad, is totally unclear to me.
Its easy to say 'see this one bad example' and the ignore a huge amount of efficiency gained by vertical integration. The idea that we have bureaucrats to have control over every single vertical integration decision by every company is pretty insane dream to me.
This reminds me of 'Indian Socialism' where you had to fill out a application for every market each company wanted to get into and the of course super smart regulator would then make sore that the 'correct' amount of companies were in each market. Of course as always there was tons of regulatory capture and corruption to say who got a permit and who didn't. Witch is basically the same pickle you want to get into, just with 100x more detailed determination about ever companies internal structure as well. A recipe for disaster if you ask me.
The idea of enlightned regulator who for each choice of each company on each level can figure if that decision is correct for 'the global population' is a total fantasy. Neither can they do it, nor would their intensives to do it actually be for the good of 'the global population'.