I think the point is that its a cost/benefit analysis. The cost of removing trust from the equation is much higher than the cost of just trusting a intermediary

I think the point is that its a cost/benefit analysis. The cost of removing trust from the equation is much higher than the cost of just trusting a intermediary. In simple terms even if my bank was evil and occasionally abused my trust to steal my money it would still be cheaper to me than trying to use Bitcoin as money and paying the high transaction fees and suffering the long transaction wait times. Sure perhaps if there was no one I could trust as an intermediary and everyone was evil and would steal large amounts of money from me then a decentralized blockchain based monetary system would be worth using. But as it is the potential risk of an intermediary abusing my trust is minimal to nonexistent compared to the very real expense and wastefulness of the blockchain based systems. The same thing applies to almost all usage of blockchain. Sure it works, but trusting an intermediary just works better, and cheaper.