On for me - SOP
There are two schools of thought on this subject. I am a member of the leave it turned on school.
With Computers, the technology is so much better today, I don't think it really makes a difference anymore. It is a matter of preference. The power savings are negligible and electromagnetic waves????
Restart them at least daily to reclaim resources. If you are a power user, then more than once a day.
Turn the computer off once a week, for at least 1 minute, to reset the Hardware.
Open it up once or twice a year and blow the dust out of it with canned air. Walmart even sells it.
As far as hardware wearing out by leaving the computer running. You are absolutely so wrong. The computer will become obsolete long before you wear out the hardware.
Leave it running and you can automate and schedule virus scans, backups, defrag etc.. to run at 3 AM.
These comments assume you are using a halfway decent desktop. You get what you pay for in computing. YMMV