Exchange doesn't have to involve profit. Really it is no different at the outset than not having currency.
If I exchange/trade you a goat for 10 chickens and I happen to know someone that will give me a goat for 8 chickens somewhere then I can make a 2 chicken profit without money being involved at all.
That concept is not created by money/currency. Money and currency just make it a lot easier. Yet they make exchanges/trades of ALL kinds easier and a person does not have to be profit driven. That is a personal voluntary choice.
And as to that 2 chicken profit. I still have to move the chickens and goats from place to place. So that is an exchange for my TIME. It may turn out that when the amount of time it takes me is determined that it isn't really that good of a deal at all. I could have been perhaps using my time in some better way.
So what if there was no exchange in the first place? Or if there was no need for exchange? I agree with you that money/currency existing in order to make exchanging/trading simpler is a good thing. it is absolutely reasonable. But it exchanging shouldn't be the be all end all.