I think giving up was once a much more viable option for our ancestors. If you simply stopped trying, stopped running, stopped chasing, stopped doing everything you could to survive, you might quickly be eaten by wolves, become a morsel for a tiger or a crocodile. Or you'd freeze or starve, fall sick and die.
Nowadays, those aren't the most likely things to happen to you if you stop trying. Not any time soon, at any rate. What's more likely is that your quality of life would begin to degrade. Ultimately, you'd slip lower and lower on the rungs of society's sundry ladders, until you wore a paper hat over a hair net, reported to a pimply faced kid, and generally wished for the merciful jaws of that kind tiger. Except the tiger is now in Las Vegas riding a unicycle. The payoff just really ain't there for modern day humans to give up prematurely. Life would basically suck more, and absent some terminal disease, suck for a long time. Society pretty much works to drag out the bitter end.
That my friends, is life: a cold kick in the ass. But on the bright side, things are never so bad that they can't get much worse.
So, in the words of Peter Quincy Taggart, Commander of the NSEA Protector, "Never give up. Never surrender!"