This is likely simply due to the fact that more homes have AC now:
... "By 1980 that number had risen to 63%, and in the 40 years since then air conditioning has grown exponentially and is now present in a whopping 95% of homes in the US according to the most recent US Census."
https://www.fixr.com/blog/2021/06/22/presence-of-air-conditi...
You might say that this is because we need it more now, but I think it's actually just that we can afford to install it now in every new home and so we do. It's just considered standard equipment.
... "By 1980 that number had risen to 63%, and in the 40 years since then air conditioning has grown exponentially and is now present in a whopping 95% of homes in the US according to the most recent US Census." https://www.fixr.com/blog/2021/06/22/presence-of-air-conditi...
You might say that this is because we need it more now, but I think it's actually just that we can afford to install it now in every new home and so we do. It's just considered standard equipment.