It's kind of like having AC in your car. You don't have to have it. You could use the 2 & 50 method (2 windows down roll'n 50 mph) and get by, but it sure is nice to have ain't it?
Same for WiFi. My old SCH-I760 had WiFi, and where I live, it was used most of the time. Work emails might filter through the radio signal every 2-3 hours (which is what I deal with on my Tour now), but being connected to my home WiFi, they would receive on my phone almost instantly.