To add to this, %ABV is what’s actually measured by distillers when distilling, unless they’re doing it entirely by smell/taste. The first and last parts will have less alchohol since everything evaporates off at different temperatures. (the tail is mostly water. the head, IIRC is mostly methanol or whatever else.)

The total amount of alchohol changes depending on how it’s packaged or sold off, or if you’re pouring a double, so people will need to do math anyhow; unless it’s a single serving package. (and even then… they might not drink it all. blashphemy, I know.)