This is a strange comparison. Cloud provider IaC offerings like Cloud Formation are obviously going to be specific to their service. AWS also has EKS for Kubernetes.

Things listed as lock in with AWS usually have easy migration paths. E.g. DynamoDB integrates with Database migration service and Lambda functions are easy enough to expose by shifting code to dedicated servers.

I don't think it's a strange comparison. Cloud providers offer a combination of services that do lock you in and don't lock you in. If you are using EC2 and SSH in to screw around with Linux, you are going to be fine if you get a better deal from GCP. If all of your deployments are managed by a CloudFormation stack and custom scripts that speak the AWS API, you are never going to be able to move. (This is not unique to AWS, of course! Everyone has their value-adds.)

A lot of the lock-in is historical. Before there was Kubernetes, there was ECS. I am sure a lot of people embraced containerization and not managing individual machines early, and are now stuck on Amazon's proprietary platform.