It's not a simple yes or no answer as it depends on what the comp is used for, how many times per day and how long each time. I advise my customers not to power cycle their comps more than twice a day of it's sued every day. OTOH, if it's infrequently used, say not for a few days but then 4 times on day, then turn it off each time. So long as you're not power cycling more than twice a day on average, it's safe to do it. Otherwise, just leave it on.
As far as wear and tear go, electronics are designed for continuous use. Leaving a comp on all the time is hardly anymore wear than leaving it off most of the time. I know this because I'm also an engineer. What does cause wear and tear is powering on or off. That stresses the electronics. Certain devices, namely capacitors, store charge. When you power up, they charge. When you power off, they discharge. Most hardware failures happen during power on or off. Of the rest, it commonly happens when there's a power spike of some kind (electrical surge.) The rest are due to age. As far as being left running continuously, there is little wear on electronics.