That would be the ideal diagram, but it's slightly more complex... because most people use 3rd party services to convert
BTC back to fiat now. In future converting everything
back to fiat would not be necessary, but for some people this is still not a option. So just add these 3rd parties to that diagram and it would look more or less the same, or even
more complex, if they had to go through their banks too, to get to the cash from these exchanges. If you hoard Bitcoin 100%... it would look like that diagram.