High Availability, Scalability, Deployments, etc are NOT the goal of Kubernetes, they are features that are not exclusive to Kubernetes, nor is Kubernetes necessarily better at them then others.
The goal of Kubernetes is to improve the portability of people by introducing abstraction layers at the infrastructure layer - These abstractions can seem overly complex, but they are essential to meet the needs of all users (developers, operators, cloud providers, etc)
Before kubernetes in order for a developer to deploy an application they would need to (send email, create terraform/cloudformation, run some commands, create ticket for loadbalancer team, etc) - these steps would rarely be same between companies or even between different teams in the same company.
After kubernetes you write a Deployment spec, and knowing how to write a deployment spec is portable to the next job. Sure there are many tools that introduce opinionated workflows over the essentially verbose configuration of base Kubernetes objects, and yes your next job may not use them, but understanding the building blocks, still make it faster than if every new company / team did everything completely differently.
If you only have a single team/application with limited employee churn - then the benefits may not outweigh the increased complexity.