Answer:
An ignition coil can fail due to a high voltage puncture of its body, or an open primary or secondary winding. A few are killed by overheating when the control side of the primary side develops a short to ground. Something as simple as badly worn spark plugs will increase the demand from the coil, and eventually lead to failure.
But if I were to discuss the current leading cause of ignition coil replacement, I would have to say misdiagnosis and bad internet information. This is especially true of modern “coil on plug” systems. Often, the actual coil is fine, and the only damage is the replaceable spark plug boot.
I've seen countless examples of online “advice” to start with replacing all spark plugs and coils at the suggestion of any power loss or hiccup. Then the car owner purchases the cheapest set of coils that they can find. Not only is the initial problem still present , but they likely WILL have a future misfire due to poor quality parts selection. All misfires are not caused by coils and spark plugs.
Step-by-step explanation: