Correct. Wears out solder joints and even more so in lower quality boards.

Tin whisker. The best I understand it, not a big problem in lead-free solder in your home electronics. In 20 years of working on home computers I’ve never witnessed a Tin whisker. In telephones, waste facilities, 40, 50 years ago, in bad environments, sure. A problem. However, in your ac controlled home with…

Agreed. I’m on the kept powered on side. Heating and cooling does effect solder joints. Eventually through enough cycles the solder will become more resistive and wear out. Even if the joint does not physically separate, the increase in resistance will alone will cause the failure. The effect is increased on budget…