> So, has trump coin and world liberty financial proven your friend wrong?

No:

1. That's not being implemented as a permanent replacement for typical currency, that's cryptocurrency as a specialized temporary vehicle for accepting bribes and fleecing the gullible.

2. Even if #1 were not true, it's rather hard for a democratic government to react when key positions in that government have (temporarily, I trust) been taken over by a cult that profits from the scheme.

> It seems that it was you who misunderstood human nature. Greed always wins.

That's an inaccurately nihilistic view of what "human nature" encompasses. If greed always won, nobody would have pets, charities would not exist, parents would enslave their children, life-insurance would just be an invitation to filicide, etc.