Bitcoin’s base layer has solved the “Double Coincidence of Wants” between 2 connected peers. This is a chimeric event that permanently transcends barter and allows specification of labor

However this comes at a price (miner fees) and is only available to connected peers - a pitiful fraction of the potential combination of coincidences to be solved.

Additionally, while we have graduated from barter but we don’t yet have commerce on par with how Fiat has connected market participants despite doing so on a terrible base layer.

Lightning’s various implementations extend the double coincidence of wants to allow many more combinations of non connected peers. How many more? That’s a problem id love to see a math student write their dissertation on.