Still the metric system uses too many symbols! .
More like the opposite is the case. Consider units of length for example. The metric symbol has metres (m). There are prefixes for various multiples and fractions of a meter, such as thousands (mm), hundredths (cm), or thousands (km). That is it.
In Imperial you have the thou, inch, foot, yard, fathom, chain, furlong, mile, nautical mile and league.
Now for volume, in metric you have the same metre, but now cubed (m3). You have the same prefixes, so mm3, cm3, km3, so it is easy to remember. There are also litres, largely for fluid measures, again with the same prefixes.
In Imperial you have cubic inches, cubic feet, cubic yards, etc, but you also have fl. oz, gill, quart, fifth, and gallon, both US and Imperial. Then there's pecks and bushels, and you also have apothecaries' measures, like the scruple, the fluid minim and the fluid drachm. So now, how many minims to the gill, without checking a table?
Weights? Metric has the gram and the tonne. Handily for some purposes, a cubic metre of water (SG 1) weighs a tonne, making it possible to calculate weights and volumes easily, including for materials of different SG.
Imperial has grains, drachms, ounces, pounds, stones, quarters, hundredweights, short and long tons. There are also two other sets of weight measures in troy and apothecaries weight systems. How many drachms to a short ton? What is the volume of a short ton of steel ingot, nominal SG 8?
