Here's a quick reference: 1) Are you on AWS? Then you don't need Kubernetes. Use Fargate. 2) Are you on Google Cloud? Then you don't need Kubernetes. Use Cloud Run. 3) Are you on Azure? Then you don't need Kubernetes. Use Azure Container Instances. 4) Are you on a PaaS like Heroku? Then you don't need Kubernetes. 5) Are you on a random VPC provider / bare metal machines? You could probably still do without Kubernetes…
I think you're overstating the investment necessary to overcome the initial complication of Kubernetes and also understating the benefit of being on a platform with a massive and thriving community behind it.
As an example, in a prior role, there were a set of data engineers that would receive data in the form of MS SQL server backups from which these engineers would need to query and transform data on an exploratory rather than production basis. Certainly one could use an "undifferentiated" service from a cloud provider, but it was also a roughly 5-minute process for me to use the rather high quality helm chart and docker image commonly available to stand up a new service for the benefit of each engineer that had the need.
The process of creating that automation necessary to deploy the helm chart and restore the backups took approximately one hour and could be repeated ad nauseum in the aforementioned 5-minute time period.
There are many, many other examples of this. Want a data-science platform complete out of the box with no vendor lock-in, how about data8.org? The list goes on.