Mechanical things suffer a lot of stress from turning on/off. But even spinning disk storage turns off automatically if desktop is idle for a certain time, it’s a balance between switch vs continuous operation, they have overlapping kinds of wear and tear.

Top of mind, you can expect 10k cycles from typical buttons and it’s hard to be less complex than a button. Because metal parts are subject to fatigue.

Flash based drives would certainly fail faster or slower depending on the number of write bytes over its life.

Then there’s erosion caused by electrons, which is my biggest suspect for the problems of last generation of Intel CPUs.