Soda is more prevalent in the big cities like NYC and LA. Google “Pop Vs Soda” and there are plenty of maps showing what’s used where. I grew up in SW PA, in the country, and I call it pop. Friend of mine not far from me, calls it soda, and he’s just as country as I am. According to the maps. I grew up awfully close to the border between where Pop and Soda are used. Vermont and NH used Soda.
There are exceptions as to any rule. A college friend of mine from Rochester, NY once asked me to get him a Coke, and when I did, he asked me why I got him an actual Coke because he didn’t specify what he wanted. Somehow, even growing up where Soda is mostly used, he called all pops, “Coke.”