Not everyone does. Some people do it to feel better about themselves, some do it out of medical necessity (chafing/rubbing raw skin, etc) and some do it for both. Also, a factor that may play in their decision is insurance and how much/what they will cover.
Honestly, I wouldn't worry about it until you have to and that should be at least a year or two after you reach maintenance (but that could change in your experience depending on your body and where the weight/fat decides to go.) Based on most of the maintainers' experiences that I've read on here, the skin improves with time but I'm not sure if that is due to them working out consistently (weight-training, to be specific.)
Let me refer you to an old thread
alleviate your fears (look through it to see some pics.) Although it's for maintainers, I still posted mine anyway and plan to again once I reach goal. Every body is different- depends on how long you've been overweight, how fast you gained it, how fast you lose it, if you work out, etc. Too many variables to really give you a straight answer.