I don't think I've ever seen a study that said that power cycling hardware made any difference in lifetime.
Power off equipment saves energy and increases lifetime.
Power supplys estimated lifetime are usually measured in hours and are more sensible to the stability of the energy (spikes, etc.) than to the number of power cyclings.
The same is valid for other electric and electronic parts.
Mechanical devices (or devices with mechanical parts, like HDDs) may suffer with constant cycling with constant temperature variations. Nevertheless, Synology, Qnap, Seagate, Western Digital (and a lot more), advise power off for increasingly lifespan.
Sub watt standby is now an increasing standard for green equipment.
So, I really would like to power off my Mac Mini when not in use, but I believe I Will need a keyboard for that because Apple do not allowed the use of the power button and JRiver (unlike in the Windows versions) can't turn Mac off using JRemote option.
Anyway, I'm a little tired of Macs and regret buying the Mac license.
I think I will stay by the Windows version.
Thanks