ECS gives you pretty much everything K8S gives you, in a fully managed package. Obviously you can't (simply) run ECS in development, but sticking with Docker Compose keeps the semantics close enough, as well as giving you advantage of clean separation from any other code on your machine.
CI/Deployment: hosted CI, merged PRs to main branch auto-deploy (I've used both Codeship and Github Actions with ECS)
My understanding is that with EKS, you still are responsible for parts of the process that are managed under ECS (for example, firewall and security rules as opposed to leaning on ALB and Target Groups in ECS)
CI/Deployment: hosted CI, merged PRs to main branch auto-deploy (I've used both Codeship and Github Actions with ECS)
DB: managed RDS