> My absolute dream would be for the DOJ to make Google and Apple collaborate on a cross-platform native app API and treat it as a first class citizen.
No. This is exactly what they should not be doing, because it requires detailed ongoing precision regulatory work.
The government is not a scalpel, it's a sledgehammer. It can easily say that the same company can't make both third party app stores and operating systems, or both video search/recommendations and video hosting. It's a clear enough line, it isn't mired in technical details, you swing the sledgehammer at the fault line between the two markets and break them apart. Then you go home.