Checks are a brilliant idea with a terrible implementation.
Idea: physical financial instrument with a specified payee (OR a bearer instrument, using the same format!), with a completely unconstrained denomination, which the payer can draw up on demand and in the field.
Implementation: reveal enough information about your account that anyone can "authorize" arbitrary transfers; take weeks and weeks to learn whether the funds are actually available and there's absolutely no way to convince your bank to reveal whether the transaction is verified, at any point; etc.
Idea: physical financial instrument with a specified payee (OR a bearer instrument, using the same format!), with a completely unconstrained denomination, which the payer can draw up on demand and in the field.
Implementation: reveal enough information about your account that anyone can "authorize" arbitrary transfers; take weeks and weeks to learn whether the funds are actually available and there's absolutely no way to convince your bank to reveal whether the transaction is verified, at any point; etc.