What features are you referring to specifically that lock you in? Sure, it's a large project. But most LOC are around being modular and pluggable, and adhering to standards (OCI, CNI, CSI). I can't think of anything that would be particularly difficult to move out of if needed.
There isn’t sufficient separation between components within Kubernetes for ease of migrating piece by piece away from kubernetes. Documentation also plays an important role in migrations. I once counted the pages of documentation for Kubernetes vs AWS for equivalent functionality (VPC, ECS, Route53, etc) and AWS had 20 pages for every page of Kubernetes.
