> Reversibility is all about trusting a third party with your wealth, which has obvious downsides.
If you do not have reversibility, you are trusting every automated intermediary, their security practices, reliability of software, hardware, etc. You have completely subjected yourself to human and computer error, and hacks. This is completely untenable.
The nature of the legal system keeps the ultimate decisions in human hands, which is a good thing. I'm not saying humans should arbitrarily be able to interfere with arbitrary transactions, but you must have the ability for a human to reverse errant transactions some way or other.
Imagine the headline, "Fedcoin bug results in $1 trillion dollar loss to hackers." Whoops.