And the thermal efficiency of the "good old days" frig (sans "D") was ?. Large heavy cabinet small interior "nasty" refrigerants.

And the refrigerants used  were HCFs, and the cabinets  used CFC-bearing insulation.

And the yearly power consumption was? A 70's model frig (sans "D") used twice as much power for the same result compared with a modern frig (sans "D")