If you go cloud, you get a handful of very large suppliers, that provide a lot of non-standardized services that are probably going to lock you in like hell (as the article wel says).
If you build infra, you're using /mostly/ commoditized supplies and skills.
If the cloud offerings where interchangeable and the industry reasonably fragmented, the margins of cloud providers would be slimmer and the paradox would probably go away (in favor of: always cloud!).
See for example Porter's analysis framework [1] and how your positioning changes in the two cases.
https://en.wikipedia.org/wiki/Porter%27s_five_forces_analysi...