@rosborne979,
As Cycloptichorn says, you can send a text to someone's non-smart phone (smart phones can receive emails, too).
But mostly it's a mode thing. For whatever combination of reasons, kids like texting.
The colored bubbles, the brevity, dunno.
But email and texting are different. (I do both depending on circumstances.)
Here's just a random example of what a TextFree conversation can look like (they have different backgrounds, colors, etc.):