Kubernetes is used by thousands of companies, big and small, has been around for more than 6 years, and is well supported by various cloud providers. There's lots of documentation and forums online with plenty help.

It'd argue that there's more documentation available than for any home-grown deployment system.

That's why I consider it battle-tested for my purposes.

Also, the post explains that boring does not necessarily mean "old". It's about using what you know best.