Agreed, noise though is not very energy dense. The amount of energy dissipated as noise (which eventually becomes heat) is vanishingly small compared to the frictional heat dissipation.Re: all inefficiency becomes heat.
technically true, but difficult to measure sometimes. The noise of a gear train isn't heat, at your ear, but eventually dissipates as heat in the larger environment. So there's a efficiency percentage lost that isn't measurable by putting a thermometer on the noisy gear case.
I freely admit I don't know the correct number, percentage of loss here! I can only point out false assumptions.
Not every energy loss is easily measured as heating the gizmo. In the real world, these things exist, work, and don't vaporize when in use. So X kilowatts of lost power isn't all in one place.