The big difference is in case of addresses you can add such checksum. So there is no reason not to.

In my API example this alone is enough to solve the problem.

Also, in case of the amount, the user can verify it, because it's human-readable.

In case of the address - he can't notice a typo that easily.

EDIT: And this is a silly talk anyway. "Let's not bother with our plane engine safety, because somebody might die of a heart attack on the plane, anyway"!