[amalag]

Do you see people printing banknotes out of feathers or some other randomly expensive material? No, and similarly mining bitcoin is some randomly expensive process. The process of securing a "coin" can be done very cheaply with minimal computing cost and the world will shift to that.

[gambiting]

The issue is not that the process has to be expensive. You are correct - we could generate billions of crypto coins within couple hours and beat bitcoin right away. But people want bitcoin. The same why people are willing to pay the price for a labour-intensive painting that took years to make over an identical reproduction that took 5 minutes to print.

[amalag]

This is now shifting the goalposts. Before it was PoW is necessary to secure the network. Now it is we don't need PoW but it is artisanal.