Like most tech stories this had pretty much nothing to do the tool itself but with the people/organization. The entire article can be summarized with this one quote
> In short, organizational decisions and an overly cautious approach to resource isolation led to an unsustainable number of clusters.
And while I emphasize with how they could end up in this situation, it feels like a lot of words were spent blaming the tool choice vs being a cautionary tail about for example planning and communication.
In my experience organizations that end up this way have a very much non blame-free culture. Can be driven by founders that lack technical skills and management experience but have a type-A personality. As a result no one wants to point out a bad decision because the person who made it will get reprimanded heavily. So they go down a path that is clearly wrong until they find a way to blame something external to reset. Usually that's someone who recently left the company or some tool choice.
The article reads to me as pretty explicitly saying that the only real takeaway wrt k8s itself is "it was the wrong choice for us and then we compounded that wrong choice by making more wrong choices in how we implemented it."
Maybe I'm reading it with rose coloured glasses - but I feel like the only thing kubernetes "did wrong" is allowing them to host multiple control planes. Yes, you need 3+ CP instances for HA, but the expectation is you'd have 3 CP instances for X (say 10) workers for Y (say 100) apps. Their implied ratio was insane in comparison.
Since you can't run the Fargate control plane that indirectly solved that problem for them