I agree with everything you said, except it seems like a false dichotomy. We can clearly build DC refrigerators with more or less insulation. We can clearly build them large or small. If you want to prioritize volume, then surely you could do that with DC. Right?

I know that a long time ago DC-to-DC voltage converters were very large in size, which meant AC would win on space efficiency. But unless I’m mistaken, that’s no longer the case. Wouldn’t a DC refrigerator with equivalent insulation and interior volume have nearly identical exterior dimensions as an AC refrigerator?