Capacitors deteroriate over time. There are 3 general factors in order of significance:
Any of these factors will accelerate failure. Most failures are a result of the dielectric material (an insulator) in the cap starting to leak some current. This results in internal heating, and either a short circuit in the cap will occur, or the current conduction and heat can sometimes burn out a conduction path in the capacitor, so it becomes an open circuit (no capacitance) or occasionally the excess internal heat causes it to vent (most have a built in vent device) or in a worst case explode.
Most times I find a bad run cap, the condensor coil is dirty. Heat kills them, plugged up condensor coil causes the unit to run hotter, and the higeher amperage also causes the run cap to generate more heat internally.
All these run caps coming in units these days are very small, wich gives them less surface area to reject heat from, and less mass to heat up during the on cycles, so they run hotter. Toss in any condition that gives them less than ideal ability to cool off and *POP* goes the top.
I find the run caps with the plastic housings to be the most reliable by far as a replacement cap.
Some units with scroll compressors are using 60 and 80 µf run caps that are very small. I like to replace them with two 30µf or two 40µf run caps in parallel.
This splits the heat generation between 2 caps, each of wich is usually physically larger than the origonal, giving much more reliable operation.
I replace far more run capacitors every year than I replace any other single type of part.
If more government is the answer, then it's a really stupid question.