It's unfortunate that I only managed to spend a few weeks of my time in East Africa exploring some of the tribal art forms. It was at some parts depressing to see how wildly they seemed to swing from tourist-centred high-grade art (which otherwise is rather commercial) to village-produced practical pieces (otherwise rather poor workmanship and/or hard to define as industry-grade). Of course, so much to say about the situation in most parts of rural Africa that stops the culture and art from helping its people make a thriving economy, but I'm not sure "a decentralisation" would be helpful now. I even think it might end up helping the exploitation at the moment.
There is first a need for several centralised well-meaning efforts to help locals be aware of the value of their products, and then to teach them better techniques for higher quality goods. And then maybe a decentralised p2p market later on once this awareness is in place. Some forms of exploitation in the current free-for-all market is that goods are bought far too cheaply by people who then improve on or copy the work with higher quality and sell it for 100s of times more.