It seems like you have only a single base unit of measurement; the rigid powers-of-ten scaling factors prevent any other useful base units from being applied, e

It seems like you have only a single base unit of measurement; the rigid powers-of-ten scaling factors prevent any other useful base units from being applied, e.g. there's nothing that approximates a foot in the metric system. So it seems a bit disingenuous to treat a centimeter as a distinct unit when it's really just 1 x 10^-2 meters. The whole "conversion factors" thing seems like a superfluous gimmick. Why would you start working with one unit, then spontaneously decide to start using a different unit in the same context? But in the unusual circumstance where you would need to switch units, perhaps due to a shift in the scale you're operating at, the metric system still prevents you from using a unit appropriate to the context, and limits you to only scaling a less appropriate unit up or down by a power of ten. It really is just scientific notation re-implemented in a bizarre and arcane way. With customary units, you can still represent quantities with scientific notation, and use inches, feet, miles, etc. as your base unit as the context demands, but you've still got a variety of base units to choose from, each more optimal than the others when operating its appropriate context.