Ammonia is still in use in large-scale refrigeration, indoor ice rinks and food storage being the major applications. The main reason it's not used in domestic refrigeration is the toxicity, although it's still common in absorption refrigerators.

It's still in use in silent (Einstein) refrigerator units.

One reason might be that we had to evacuate our office when our small refrigerator in the pentry popped and vented all ammonia. It took a while to get sorted, and it can't have been much in that small unit.