Stackoverflow is both asynchronous and asymmetrical. The former lets the dev answer when convenient. The latter means the dev knows that their time is being multiplied and potentially lending help to large numbers of other devs over a large period of time. That is a compelling idea. A phone call is one-to-one and inconvenient. $45/hour is also hugely underpaid in the US at least. So, the proposed system is underpaid in both $$ and personal satisfaction.