OpenShift is just k8s with batteries included so the batteries are in a real sense a lock-in to the OpenShift community so take that trade-off as you like. I wouldn't mind, but since your initial post was in the fear of lock-ins, this may be a start.

Other examples: - full spec S3 (the basics are well copied at this point) - GraphDBs I've found are very different in many ways between cloud vendors - k8s load balancer bridges are different for each vendor though the big three have more or less feature parity with one another, just different impls

Just as with OpenShift, you'll start to see trade-offs between vendor convenience, 'lock-in', and cost which you'll ultimately have to choose what's more important to your business in the end.