ArgoCD does a great job managing application "deployment" configuration across multiple k8s clusters. It does an equally well job maintaining "core" or "baseline" configuration across the clusters (e.g. ingress class CRDs), including the intrinsic ability to manage itself.
It works by watching for configuration changes in registered git repositories and performing a "sync" whenever there is a difference in the manifests it has applied (aka "live") and the ones in git (aka "desired"). "Syncs" can be performed automatically, through the API, or manually -- and the configuration repositories are typically polled for changes every 3m.
This concept of responding to and applying infrastructure configuration changes in response to a git repository's state is called "gitops".
This model can have an advantage over imperative models because it leans towards determinism (its own configuration as well as application configuration is declarative and available in a way that can be easily rolled back, audited/reviewed, and centrally maintained).