I think you are proving the point; there are very, very few applications that need to run on two cloud providers. If you do, sure, use Kubernetes if that makes your job easier. For the other 99% of applications, it’s overkill.

Apart from that requirement, all of this is very doable with EC2 instances behind an ALB, each running nginx as a reverse proxy to an application server with hot restarting (e.g. Puma) launched with a systemd unit.

To me that sounds harder than just using EKS. Also, other people are more likely to understand how it works, can run it in other environments (e.g. locally), etc.

Sorry, that was a misunderstanding. I meant that I want to be able to run it on two cloud providers, but one at a time is fine. It just means that it would be easy to migrate/switch over if necessary.

Hmm, let's see, so you've got to know: EC2, ALB, Nginx, Puma, Systemd, then presumably something like Terraform and Ansible to deploy those configs, or write a custom set of bash scripts. And all of that and you're tied to one cloud provider.

Or, instead of reinventing the same wheels for Nth time, I could just use a set of abstractions that work for 99% of network services out there, on any cloud or bare metal. That set of abstractions is k8s.