OCP4: High idle CPU usage?

Hello,
I recently installed my 1st OCP (4.8.12) cluster (user-provisioned installation method at Proxmox virtual machines).
Since it's going to be just a small test environment I went with a very minimalistic approach - only 1 combined master&worker node (4 vCPUs, 16 GB RAM, 100 GB disk).
The installation was successful and this cluster is running now.

However I noticed that the CPU utilization on the machine is constantly hovering between 15 and 25% which means it's able to fully utilize 1 CPU core while doing nothing yet. That's quite unexpected especially when compared to "pure" Kubernetes cluster where the idle CPU utilization tends to be much lower.

Most of that goes to the kube-apiserver and to a lesser extent kubelet and prometheus (which causes just some brief spikes). When I checked logs I didn't find anything special, just some regular metrics collection (probably telemetry), but nothing that would explain that constant utilization.

Can someone more familiar with OCP tell if this is sort of normal behavior?