Brilliant suggestion ! I agree with you; But like jerry said above it should be implemented in such a way that irrespective of where you are, you can quickly exchange Steem with your country's local currency with ease. Example , I am a Nigerian, I should be happiest if with a click of few buttons , I exchange my Steem to Naira (NGN) , not USD or EUR, etc.
This will definitely empower a massive community of new Steemians from all over the world.
Yes you are right... I mean, the seller unlocks when he receives the fiat ☺
Thanks for clarifying