Progressive taxation of companies
I know this sounds outrageous, but hear me out. What if monopolies split themselves? Wouldn't that be great? Does the same company really have to make the phone and the charger? No, but there are 2 reasons apple does:
1. Collaboration between the phone department and the charger department is slightly easier.
2. They can abuse their monopoly on iphone chargers to force you to pay more for them.
Apple makes about 30 billion on iphones per quarter. Assuming all iphones were $600 (which they arent) and everyone uses 2 chargers per iphone (because the first one broke) priced at $20, apple would be making $2 billion from chargers.
Say, if they didn't abuse their monopoly position for chargers they would make only $1.8 billion from them.
This is $2.0 billion - $1.8 billion = $0.2 billion less revenue.
Now if you just tax apple progressively such that taxes for 32 billion in revenue are more than $0.2 billion higher than paying taxes for 30 billion in revenue, apple will split into iphoneapple and chargerapple by themselves!
Now in practice you might not want to tax revenue but for example the value of the company or something else.
Also you don't want the 'split' companies to still behave like they are one company, this means that you want the split-off company to have different shareholders from the main company, because otherwise they would just behave in mutual interest.
More in line with the topic, netflix might decide to split into a 'movie suggestions algorithm' service and a 'movie streaming' company.
Google would split into a gazillions of different companies.
But some interoperable internet legislature might be a little more realistic :)