Why do Americans still predominantly use texts to communicate?

The thing that confuses me the most about the whole green/blue text bubble discourse (people giving their number to others, receiving a green text indicating the other person is not using an iPhone and telling them to f off because they only date iPhone users) is very simple: why do Americans still text? Europeans have been communicating through WhatsApp pretty much exclusively for about 8-10 years now. I hear a lot of Americans falling for text based scams and that is not even an option because I never text. We just use WhatsApp. Is WhatsApp not as a big a thing there?