I was interested to understand more from the male point of view how/why this area had developed.
Maybe you would be better posting this on a punter based forum to get the male perspective, because I feel on safe there are very few men that will post and the clients that read this forum are mainly lurkers.
As for GFE, personally I think there is a huge difference between a sugar daddy relationship and GFE.
I advertise an excellent GFE and to me that means offering the gentleman the perfect companion, being charming, interesting, flirtatious and entertaining as well as sexually willing and as adventurous as he wants to be (within reason). Basically ensuring for the time he is with me he is the centre of my universe. If he wants to take me out in the frame of the working agreement lovely, but not essential, gifts of any sort are accepted with genuine delight, but certainly not expected. Since I enjoy meeting and interacting with people, love sex and am a pleaser by character, I don't find this difficult and genuinely enjoy the encounters.
A sugar daddy is taking that relationship a step further, I'd expect to be at his beck and call all the time in exchange for making him feel good for buying things for me. i couldn't do that and respect myself the next day, sorry.
And a boyfriend is an entirely different matter, this is the guy who gets to see you warts and all, he knows what you look like when you are full of the cold with tissues stuffed up your nose to stop it dripping, endures being snapped at when you are in a bad mood, shares your triumphs, supports you and asks you for the same. A partner you can share all aspects of life with.