[steve1977]

It loosens the coupling between A and C of course. But it introduces coupling between A and B and between B and C.

So instead of one tight coupling and two components to manage, you now have two tight couplings and three components to manage.

[mrkeen]

Yes. That's what decoupling is.

Instead of one tight coupling between the customer and the coffee machine, you have two tight couplings: one between the customer and the barista, and one between the barista and the coffee machine.