In 24 years I've only rarely seen scenarios that actually require something at the level of complexity that k8s represents. I worked on Bing some years ago, and it would definitely have benefited but MS rolled their own solution (which has since been replaced by I don't know what).
I've seen k8s USED many times where it was wholly and completely unnecessary and being pushed by juniors who wanted to go apply to Google in a year or two.
I am currently running a service that receives 3000 rpm spike and averaging 500k requests a day.
On a single server behind cloudflare deployed straight from Github.
We have a version of the service also running on ElasticBeanstalk with a single server.
Neither experiences downtime.
People severely overestimate their needs.
Google, Facebook, Microsoft, Amazon? Are serving literally billions of requests per minute. They have a need for that level of complexity.
Most of us here... do not.