Only reason I could think of would be if I wanted to scale etcd far larger than I wanted the control plane.
10/19/2022, 8:12 PM
If your control plane had slow storage or non local storage it might be worth moving etcd off the control plane nodes. But normally most people just keep the API, controller-manager, scheduler and etcd all on the same nodes.
It's more just a flexibility thing than a recommendation or need.