The main benefit you get from managed Kubernetes solutions is network/security, update- and scaling-related. These things are important, but they don't reduce the daily operating complexity around deployments (applications) on the cluster. In other words, they take the pain out of running and setting up Kubernetes itself, but they don't simplify using Kubernetes. I highly recommend using a managed solution unless you absolutely know what you are doing in terms of networking, security, and disaster recovery. They are not too expensive either, you're still mostly paying for the VM nodes.

The only reason we're not using a managed solution is because we have some specific edge networking and multi-cluster requirements that are hard to do with a managed solution.