Rest lowers the symptom, not the underlying issue.
The most common response to post-run knee discomfort is to sit it out for a day or two, let it feel normal again, and go back to the same routine. And it usually does feel normal again — for a while. But if nothing about how the knee is loaded during that recovery window actually changes, the same ache tends to come back, often triggered by something completely unrelated to running: a flight of stairs, a squat to pick something up, a long day on your feet. Rest treats the flare-up. It doesn't treat the window of vulnerability that caused it.