That's fair. As I pointed out in another reply, most of my experience is with GKE so I may be spoiled in how painless it is. All I can say is that GKE is treating me well. Node upgrades are seemless, defaults are decent, it was very easy to create clusters through the console or terraform. I only run 5 clusters and that is not that huge compared to others.
I've used ECS more than fargate. My biggest problem comes from reliability and having to manage things. We still run things on ECS and we get about 30x as many maintenance things we need to do, like retiring instances or instances just dying on us and we have to move things off of it manually.
I have a little bit of experience in Fargate from a previous job but not enough to make a real conclusion about it.
I've never used EKS but I do have friends that would rather roll their own version of Kubernetes on EC2 instance instead of using EKS.
What were your pain points with ECS? Did you use ECS with or without fargate? What about EKS, since that sounds like a closer equivalent to GKE.