I feel like OP would've been much better off if they just reworked their cluster into something sensible instead of abandoning K8s completely.

I've worked on both ECS and K8s, and K8s is much better. All of the problems they listed were poor design decisions, not k8s limitations.

- 47 Clusters: This is insane. They ack it in the post, but they could've reworked this.

- Multi-cloud: It's now not possible with ECS, but they could've limited complexity with just single-cloud k8s.