This will probably start to change if this is now the reality but at least historically the reason Europe didn't have air conditioning was it wasn't worth it for the 4 days of the year that it would be used.

The other reason being that houses won't design to be air conditioned, we don't have ducted heating so if I bought an air conditioner and had it installed in a room it would air condition that room, if I wanted air conditioning in my house I would have to have a unit fitted in each room, that's going to get expensive. Alternatively I could buy this £15 fan from Lidl.