My house was haunted. One of the lights would randomly go on or off and random times without anybody fiddling the switch.

The previous owner of our house had installed fancy dimmer light switches. On a whim, we replaced one of the fancy switches with a simple on/off switch.  As we took the old fancy switch out, we noticed that it had capacitors, a circuit board, resistors, even a microchip! That's a lot of different things to break down.

The new simple switch worked great, and the associated light no longer randomly toggles. So I conclude the fancy light switch was the problem.

Furthermore, the dimmer switches were more complicated to use because they had some fancy pressure touch thing: a quick fast press would toggle the light; a soft press would dim the light. It took us a while to get used to them.

When I was at Home Depot, the fancy switches were $40; whereas the simple on/off switches were ~$3.  The old simple switches throughout our house are still working; and we never really needed the dimming features for the fancy switches.

So the fancy switches were more expensive, harder to use, and haunted. Overall, not an ideal tradeoff for our needs. We'll stick with the simple on/off switches.

 

I think the same things applies to software design. You can build complicated software with lots of features, but that also means more places where it could break down. If a simple solution does the trick, it may not only be cheaper to build, but easier to use and cheaper to maintain in the long run.