> I think all big cloud providers replaced etcd with a custom in house implementation in their K8s offerings for this reason

This is incorrect.

AWS, Azure, GCP still use etcd in their customer kubernetes services.

"EKS Ultra Scale" uses an in-house Journal

GKE uses spanner (with an etcd API layer) per the docs.

https://docs.cloud.google.com/kubernetes-engine/docs/concept...

https://cloud.google.com/blog/products/containers-kubernetes...

TIL!