> it has been successfully replicated by almost every organisation without mainframes

yeah but how much did it cost?

At a large financial news company I worked for, the AWS opex was £4m, All to put text on a page. You know, a solved problem. We spent years fucking about with fleet to make something "resilient". (then early, shitty k8s)

The opex for FAANG is astronomical. facebook spends something like 40 billion a year on infra. Thats without staffing costs. (manifold, the S3 clone, is a bastard to use.)

My point is, which I should make more obvious: if you buy the right mainframe, you can literally blow one of them up, and not loose any uptime. Yes, its expensive.

But, hiring a team to fuck about with k8s on AWS is going to cost more, and never be finished, because true redundant systems are hard to design and build, even by distributed systems experts.