We already have well trodded solutions for these dominant market players: we don't nationalize, we regulate so as to maintain competition. The railways, phone companies, electricity and water, there are many examples of national services that started out as private, led to market failures, then were nationalized and failed to provide adequate service, then were re-privatized in the 80s and 90s as well regulated monopolies.
There is no fundamental reason we shouldn't to the same for things like the App Store, Amazon, Starlink etc. These are all services with a technical exclusivity, strong fast mover advantage or very large entry barriers that are ripe for monopoly abuse. Regulating them would mean setting maximum fees to reasonable values based on costs, ensuring open and competitive access and preventing the platform from front-running its customers etc. For example, monolithic railways were broken up in Europe into distinct infrastructure and passenger/freight arms, with the infrastructure open to all competitive rail companies. In the same vein, Amazon should not be allowed to front run its own customers, the platform and fulfilling centers should well separated from whatever commerce Amazon itself is doing.
The fact that these digital players remained unregulated for so long is more the result of government inertia as well as national interests - for the first time, we have truly global monopolies, and the benefit US for example reaps from having such dominant champions outweighs the damage to its own consumers, so they let them "innovate", especially since regulating them would mean to open these platforms to foreign competition that is not similarly regulated.
So it should not be surprising that the EU is the most aggressive when it comes to this area, because it largely lacks similar platforms. But to regulate global services effectively, we would need truly global regulators, or at least national regulators of OECD countries acting in concert.