Kubernetes ought at least to be the right tool for a wider range of compute task. And I think it could have been the right tool for a wider range of compute tasks.
For instance, I don't regard one of our products that runs in three availability zones and has 3-4 instances per AZ as being "large scale". It is still a small system. And it doesn't run in multiple AZs for performance reasons but because we really need high availability.
We embedded discovery, failover and automatic cluster management in the server software itself. But it isn't really how we'd like to do it. But it is still less of a hassle than running K8S. (It also means that we can do that if you license our software to run it on-prem on pretty much most runtime environments, and that has its value, but again, this isn't functionality you want or should have to do yourself)
At ~12 instances probably still in "pets aren't so bad" territory.
k8s is not the right tool for every job. Most companies are not at the scale where they need to worry about the problems that it's trying to solve. But it's a cargo cult - they see the blog posts about how moving to k8s solves a bunch of problems that come up as you scale and decide they need to be solving all of those problems also even though there are simpler solutions at their current scale.
There's a bunch of other platforms out there that are way more opinionated and less "awkward" but they don't have the buzz that k8s has.