I agree about what you say about decentralized exchanges and the developing world.

But I still maintain that no single blockchain will ever be able to scale to the level necessary for mass adoption without very heavy mining centralization. I'd say decentralized exchanges and atomic swaps between chains in addition to mesh networks such as the Lightning Network are required for mass adoption. The value of Bitcoin may rise to the tens of hundreds of thousands per coin only if becomes generally accepted as a digital store of value ("digital gold").