$ETH Transactions that are completely non-cancellable are actually impossible to carry out, as financial institutions cannot

avoid dispute mediation. Mediation costs increase transaction costs, limit the

practical minimum transaction size, and cut off the possibility of casual small transactions,

and there are broader costs in losing the ability to make irreversible payments for non-cancellable services. With the possibility of reversal, the need for trust spreads. Merchants must

be wary of their customers, forcing them to provide more information than they actually need.