I don't think 80 Plus ratings measure anything more than straight up efficiency in few designated ranges .
True but to meet those lower efficiency ratings they use lower quality/cheaper parts which have a tendency to best case fail or worst case start a fire.
A PSU having lower energy efficiency such as 80 Plus, means that on average that PSU will not last as long as a higher efficiency part like an 80 Plus Gold, Platinum or Titanium.
Heat is the enemy of electronics and so the cooler you can make them run the longer they will last.
An 80 Plus rating literally means it will generate more heat than an equal wattage Gold or higher.
Something of higher quality like the
Corsair AX1000 with its 80 Plus Titanium rating has a 10 year warranty showing that Corsair believes it will last at least 10 years.
For comparison the
Thermaltake Litepower 750W ... aka the firestarter ... has a 2 year warranty with its 80 Plus rating.