what are these components?

MrWizard wrote:
Movs ... Are sacrificial Because they degrade , and eventfully fail completely

First, how does one know an MOV has degraded? Nothing (ie indicator light) reports it. An MOV manufacturer describes how to test MOVs for degradation.

The change of Vb shall be measured after the impulse listed below is applied 10,000 times continuously with the interval of ten seconds at room temperature.

IOW MOVs must be removed and connected to complex electronic test equipment. Virtually no one will do that.

Second, MOVs must fail without any visual indication. That means it still works - but at a different voltage (Vb). MOV that stops working completely fails catastrophically - with visual indication. MOV datasheets are blunt. Catastrophic failure must not happen.

That indicator light only reports catastrophic failure. It clearly cannot report degradation.

Third, you are technically correct. High/low voltage and reverse polarity are not surges. What is called a surge (by engineers) is not a anomaly typically found in campgrounds. Marketing has its own interpretation for "surge".

Asus motherboards also have a completely different interpretation. A slightly low DC voltage is reported as a surge. USB port has another completely different definition. A 500+ milliamp current is a surge. How does any of this relate to a hundreds or thousand amp current mode spike that only lasts for microseconds? The word 'surge' is a subjective and ambiguous term when defined by marketing.