I never look at it as a competition though I know most do. I look at it as filling a desire that only grew as their boobs grew. Beshine & Foxy feel this; though probably neither thought they would be this size when they started, the desire to have bigger boobs kept them wanting more., hence the phrase boobie greed was born to describe the feelings they were experiencing.
Like you, I reflect on Chelsea sadly. She never asked for expanding boobs and though they brought her fame & fortune for awhile, she never really liked the inconveniences they cause, so her life was often filled with sadness; huge boobs was her calling card, but she never really liked them.
On the opposite side of the coin, Foxy & Beshine both tell a similar story; they love the way their boobs change the way they live life daily. It may be hard to accept, but for those select few, having huge boobs far outweighs any problems they cause. Ask Llelwyn, she would tell you how much if would mean to her and she already knows big boob as she is an L cup. Another princess that I corresponded extensively here and in emails that shall remain nameless, an O to P cup herself, felt the same way; she wished she could have boobs so big that her husband would have to help with everything. I think that Keisha Evans was of that frame of mind, among others, but like the others, she could not afford the surgeries to follow her dreams, so they probably faded away. A sad story.
I know people want to think it is all chasing the title and all the hyperbole that accompanies such claims, but to those that actually love having huge boobs, I don't think they care about those things as much, leaving those exaggerations to the people writing the releases or the posts on their websites. They just want to enjoy the feelings that their huge boobs give them. Everyone has their own things in life that they cherish.