I think that makes a lot of sense in music or other "divide this up" tasks that don't require concrete objects but that's not most of what the metric system dea

I think that makes a lot of sense in music or other "divide this up" tasks that don't require concrete objects but that's not most of what the metric system deals with. And time isn't decimal-based at the larger-than-one-second level, after all. But in the world of concrete objects "eyeball this into two pieces" is much less useful and less common than "ok so we need to account for the extra 3mm of this extra piece so add that to the 44mm base measurement" - which is much more straightforward than something like "add 3/32nds to 1 and 3/4 inches." especially if you don't know that you're gonna end up with a measurement in the 32nds when you make the first measurement. Or larger-scale like "we went six hundred feet already, we needed to go a mile and a half, how much is left?"