Well managed on-prem vs. the "normal" "normal"
All these issues with public cloud being more expensive (on the long run) than keeping your own iron bog down to one simple measurement: how well they are managed. And I'm starting to suspect that there is a bias in the comments. Look, the reality is that Reg commentards are likely a notch or two above the "normal". Their "normal" is a understaffed enterprise team trying to support an overhemly number of legacy systems with a tiny budget and coming up favorably in a cost comparison because they are motivated enough to keep learning and applying common sense to complex problems.
Whereas the "normal" "normal" is a bunch of old timers that are still trying to get basic technology right (TCP, DNS, AD, etc), whose training has not been updated in the last decade, that fear change like a plague and that spent their days fire fighting their own created monsters. And in these contexts, public cloud is a blessing: cheaper, works almost every day and provides technologies you can only dream of in your current environment.