Earlier quoted context omitted.
Checked my Samsung 970 Evo 2TB and it says 487 even though it’s been on continuously for years.
Receiving power isn’t the same as being “on”. I’d assume the drive has a sleep state that it goes into after inactivity, and those hours don’t count as “power on” hours.
"Power On Hours: Contains the number of power-on hours. This may not include time that the controller was powered and in a non-operational power state."
The same drive reports only 329 "controller busy time" minutes.