You do not actually understand how bitcoin works.  Proof of work isn't "work", it's spending money to put metal boxes on cruise control to generate interest.  Anywhere there is interest involved, there is usury.  They are not miners or transaction validators and they are not doing work, they are rent seekers.  If bitcoin was the world reserve currency (god forbid), and you're one of the tiny amount of mining monopolies demanding a cut of every transaction, you are practicing usury.  

You see, so called "proof of work" is really just externalized proof of stake in practice.  There is no real difference besides the external stake has a slightly higher chance of eroding than an internal one.  Both schemes generate interest and where there is interest, there is usury.  The only way out of that paradigm, like I said, is for everyone to process their own transactions like email PoW - unprofitable PoW style.  As I also said, IOTA was the closest attempt at that, but it's not possible to form consensus in a DAG without artificial convergence, so it's a failure - an easily predictable failure because it's not possible to create a decentralized digital currency.