People use Bitcoin as a form of gold 2.0. Thats why the MC is where it is. Nobody in their right mind is making a cash flow case for btc unless you include lending which actually makes a decent return.
It's true that people use it as gold 2.0 and it's the bull case. But, the value is approximately 100% speculative. If people for some reason decided they will only use it for transactions and not as investment, most of the value would disappear.
