The general idea would be breaking things into viable businesses and imposing compatibility with competitors. So, for Amazon, spin off the delivery and allow others to do the driving around, provided they can meet the same requirements around picking up from the warehouse and so on. For Google, spin off the DC operations. And so on.

It becomes harder conceptually if you try to break things in the software layer. Working in Google, I just cannot fathom what would it take to actually allow competing ads platforms in search.