Dark and AMOLED are not the same mode, and the difference shows up on your battery
Most people view the two as one switch with a nicer name, then wonder why an evening that felt easy on a phone feels heavy on a laptop. They are different decisions about the same surface, and each one trades something away. Knowing which trade you are making takes about a minute and saves a lot of squinting.
True black earns its keep only on monitors that can switch a pixel off, where a dark area uses no power at all. That is the one case with an effect beyond aesthetics, and it is measurable rather than felt. On a backlit screen the same choice is pure style, since the light behind the glass remains on regardless of what the palette claims.
The big surface everything else sits on has one job: to stay out of the way. Push it too light and every accent starts shouting; push it too dark and thin text loses its edges. The comfortable range is wider than people expect, but it is not unlimited, and where you land in it changes how the same accent reads — which is why two schemes built from one pair of colours can feel like different products.
Both variants sit together on one page, so the comparison is a glance rather than an argument: brazil edge theme opens a page where the modes can be flipped in place, and country flag browser themes lists a few hundred ready-made sets.
The sensible rule is plain but reliable: on a backlit display take the rich variant and enjoy the readable edges, on a self-emitting one take the black and check that the quiet end was really reworked.