There are certain core services in macOS which takes up a significant amount of your CPU and RAM. I don't use iCloud so nothing synchronises but, still Safari needs to run Bookmarks Sync Agent for no reason. I have removed/unloaded the .plist file for Safari Bookmarks Sync Agent. Unloading the .plist file works but doesn't stops the service from restaring during the next boot-up, in order to stop it from restarting you need to delete the associated core service agent. Now deleting a core service (Safari Bookmarks Sync Agent) screws up the OS. So is there any way by which I can safely unload/remove coreservices without screwing up the OS. I searched the web but I coudn't find any answer to my specific question.