To dramatically oversimplify it, a big part of the US craft brewing industry came out of the Pacific Northwest, where there was a two-decade-long race to see who could brew the hoppiest, strongest IPA. ABVs rose to the mid-teen%, until people realized that super-bitter, stronger-than-wine beers weren’t very tasty.
You still find plenty of 7.5-9% ABV IPAs around, but that’s what session IPAs are for. Session ales typically have 3-5% ABV and are great for summer.