AC is way more space efficient than previous ways of cooling buildings and far more flexible. Another way people used to deal with the heat was just not working

AC is way more space efficient than previous ways of cooling buildings and far more flexible. Another way people used to deal with the heat was just not working during the hottest portions of the day, there also used to be a lot more non-working time. AC lets you work continuously through the whole working day which is a big productivity boon. There's benefits beyond just energy usage to consider when we're evaluating cooling methods.