It's an attention to detail thing. For spectacular fails, look no further than
https://www.skyatnightmagazine.com/space-missions/what-was-wrong-with-hubble-mirror-how-was-it-fixed/
and
https://www.simscale.com/blog/nasa-mars-climate-orbiter-metric/
This second one I use as a case study on why we use an internationally agreed set of units in science and engineering, and what can go wrong if we mess units up...