My knowledge is out of date now, but the main issues IMO are/were: - No concept of apiserver rate limiting, by design. I see there is now an APF thingy, but st

My knowledge is out of date now, but the main issues IMO are/were: - No concept of apiserver rate limiting, by design. I see there is now an APF thingy, but still no basic API / edge rate limiting. - etcd has bad scalability. It's a very basic, highly consistent kv store that has tiny limits (8GB limit in latest docs, with a default of 2GB). It had large performance issues throughout its life when I was using k8s, I still don't know if it's much better.