It's almost exclusively a cultural norm. In SE Asia they often have a spray hose next to the toilet. In Korea and Japan they have bidet functionality integrated into the toilet. In the middle east they dump into a hole in the ground.
That's just false. In every country in the middle east, in any house, you'll find an integrated bidet and probably a hose next to it. Even the most down trodden facilities in my country had bidet.
I can't say the same for North Americans who apparently just think wiping is enough.
Syrian, Turkish and Jordanian toilets were no picnic but I've never seen worse facilities than the ones in Egypt. I remember having food poisoning after dining in Sinai and the next day a boat took us to Jordan. However much I needed to use the toilet on that ship it wasn't enough, I couldn't face it. Maybe it was the rough sea conditions that caused there to be shit up the walls and on every surface.