As someone originally from Texas (where there generally are no basements) who now lives in New England (where basements are ubiquitous), this was always an interesting question for me as well.
The reason is the frost line (i.e. how deep the ground freezes in winter). You don’t want the ground to freeze below your building footings, or it can result in frost heave and structural damage. So you have to excavate down deep enough to pour your concrete footings below this point. In Texas, this may only be a foot or two. In New England, it’s more like 5-7 feet. And in New England, as long as you’re excavating that deep to place the footings, you may as well excavate the interior portion as well and voilà!: there’s your basement.
There’s also the cultural reason that people now expect basements in northern climates like New England.
The only house basement I ever saw in Texas was in Army housing at Fort Sam Houston, probably as a result of builders not from the region who didn’t know any better. It actually was great to have, because we didn’t have A/C, and it was the coolest place in the house.