You are correct. With most modern systems stock is more than enough, when you game the real-estate of your screen or screens are what determine if you need to OC at all. Any standard single 1080p screen regardless of size coupled with a good graphic card will not need the CPU to be OC'd to get great performance.
Start gaming with three screens or a 4K screen and multiple video cards then that all changes.
Bump up the refresh rate and your CPU will work harder, and your graphic card too of course. Again it is all dependant on the number of pixels that are being refreshed. Most of the time a high end CPU and graphic card at stock will be up for the task. Think there are only a couple of games that really depend on CPU processor power to the extent that you allude to.
OC is just fun for most of us, a sport for some of us and a job for a few of us.
To help us help you - please provide as much information about your system and the problem as possible.