I wonder also.
Refrigerator - no such thing of preventive change of compressor oil, use until spoil, norm to use 5 to 10 years never change.
Room air cond - never heard of change of compressor oil also, only top up if gas no enough, or wash blower when dirty. Last time I asked maintenance people, they said already got lubricant within.
But for Car - need to periodic change of compressor oil?

I taught all work the same principle
or car use different compressor mechanism?