That said, Imagine Alice works for 8 hours to find and bottle clean water.
Bob spent 8 hours hunting for food.
They exchange 4 hours' worth of water for 4 hours' worth of food. They both profit, because without food, Alice would starve to death, and without water, Bob would die from dehydration.
Value is not necessarily the same for everyone, you can have situations where everyone profit.
You did not account for opportunity costs: each of those items were "worth" (futureofbitcoin) - to use your phraseology - the amount of time it would have taken Alice and Bob to acquire them after having starved and dehydrated respectively. However, neither Alice nor Bob forsook that quantity of time. So, the assurance of profit deprived each participant of what they "needed" and assured them only of what they already had in (at least, relative) excess.
Money extrapolates such deprivation to international markets.