I have been flying since 1976 and have never had a primary flight control fail or jam. I had one significant emotional event when the elevator trim on a T 28 Trojan was connected backwards.
However I blame myself as the flight was the first test flight after the aircraft was completely reassembled after a a major rebuild. I checked for full movement of all controls and correct movement of the ailerons, elevator and rudder but did not check that the trims were moving in the right direction just that they went to full travel
The resulting test flight was more exciting than it had to be but in the end I had an opportunity to find the fault on the ground but did not. I am willing to bet that many of the examples of jammed controls presented a similar opportunity....