It's nothing new. In 2003 there was a huge heatwave and thousands of people died:
https://en.wikipedia.org/wiki/2003_European_heatwave
The reason is simple to understand. For the majority of the time the AC would sit idle. Some years AC is not required at all because the summer is mild. It's hard to get people to spend money on things that they don't need most of the time, it's like buying insurance.
Ok but you can use AC in the winter as well, you've an use it only to dry the air in your apartment. So this is not a real argument to me once you know what it can do and how it does it, there is no reason not to have one. Outside it is 25°C but I still run my AC at 22°C and it is super efficient as this is the case where AC excels at efficiency when the diff is small. It is a heat pump, sometimes I would run it when outside is colder and inside is veru warm as it moves heat faster than opening the window and waiting.
I know not AC are/were heat pumps but I don't know of any that are not anymore
or (to put it in an IT context) backup and DR services/hardware.
There were 2-3 days a year above 30C in London from 1995 to 2015. Since then it's been about 6 days a year, and this year has already broken that
> nothing new. In 2003 there was a huge heatwave and thousands of people died
It's completely new both in absolute temperatures, frequency and length of the heat waves