I'm sure not worth 2.7 Billion and I'm not famous, but for the record, I use a flip phone too. Two, actually. One for my office emergencies, which luckily are infrequent, and one for me personally. The personal one isn't on very much of the time. People can reach me at home. If I'm out doing something, I want to be out doing what I want without interruptions. Close family and close friends know that when I don't answer my personal cell phone, they can get me on my office number and I'll recognize their number and answer the call.
I use my phone to make phone calls and receive important messages, so I don't need or want anything else. I'm not a chatter and have no desire to text.
I don't want to be any more connected than I need to be.
Not a flipphone although i think its kinda cool still ,an i iphone wont last long in my business , i use this one , its straightforward and quite shockproof