Does powering down a PC via power button harm it?

It is true that powering down a computer through a power button will harm it. Because, every time when you will push the power button, it will decrease the lifespan of the power button. Moreover, as you push the power button, there will be a small spark, which will trigger in the button circuitry. Every time the spark will happen, it will proceed further towards the wear and tears level. When you push the power button fully, it will instantly draw the maximum current from the SMPS circuitry and make other electronic circuitry invalid for the couple of seconds. When the ignition of the motherboard gets momentum completes, then the other electronic circuitry will back normal. However, you have to remember that during this very short period, the sophisticated electronic circuitry can be damaged. After, the long uses of the power on/off procedure, you will may face the power button in non-functional mode or erratic behavioral mode. As, it will harm your computer badly. Therefore, it is better to keep the power button on always and you should operate the on/off procedure directly from the UPS power outlet. It is a good option for you and your computer. So, next time when you are going to power on your computer, never forget to power off it directly from the SMPS power outlet.