Icebound wrote:

It is not the exchange that creates value. It is the work, the labour.

In fact, it is both. If you have something that you value at 10 but I value
at 15, and I buy it from you for 12, then the net value has increased: I've
gained 3 and you've gained 2.

This doesn't only apply to things; services are subject to the same effect.

This is also why investment works. I give you 10 to use for a while. You
use it to make 5 more, and pay me back 12.

Sure, work plays a role too. But if we assume that you bought labor
(another word for "service") with that 10 I loaned to you, then absent the
loan of 10 that service could never have been purchased.

- Andrew