It seemed wild to me too, but I double checked and I don't see any errors. Here's the data and calculations, annotated with sources. https://docs.google.com/spreadsheets/d/11hd-Q6KdkNETiRBs_JYw...

Keep in mind that these are companies that made a big bet when Bitcoin was in the 50-65k range that it would keep going up. They planned their expansion based on that scenario, so it's not that crazy that they allowed their margins to get so slim.