My guess is that, whenever there's a possibility of innovation then competition is great and private corporations are the best; but when that period comes to an end, when the private corporations naturally merge together to save money by eliminate duplicate functions or improving scale efficiencies, then government buy-outs, nationalisation, is the best — everything that would have been a shareholder dividend, instead becomes a taxpayer saving.

Even if this is correct (unlikely, I'm not an economist) I have no idea how it would interact with globalisation/multinationals.

I'm not sure what amounts to "personal computing" is quite a natural monopoly, but it is important and foundational enough for modern life that it deserves special protection.

Personal computing is not quite a natural monopoly because it's easy to buy a different device but the rent seeking app store and not letting users install their own software is absolutely an anti competitive monopoly.