It's worth remembering that Imperial measurements AREN'T completely illogical. For the most part they are trying to make sure that the numbers you deal with in everyday life are all small, approachable numbers.
For example,
Is it easier to picture what someone 170cm tall looks like or is 5 foot 7 inches?
Is it easier to picture what a 63kg person looks like, or a 10 stone person?
Is it easier to picture what 2 pints of orange juice looks like, or 1.14 litres?
Humans tend to like using numbers like 5, 7, 10 or 2 more than they like numbers like 170, 63 or 1.14.
And WHY (for example) 12 inches in a foot? Well 12 is a very divisible number, so it allows you to do a 1/3, 1/4 or 1/2 of a foot in whole numbers of inches. The same reason why 24 is a great number for hours in the day, and having a "metric" day of 10 hours wouldn't be so helpful.
However, once you start to do calculations with them, then metric units become easier. If you had to calculate the total length of 20 planks that are 3 feet 7 inches long that becomes a mess compared to doing 109cm x 20.
In today's modern world we do a lot of calculations, so metric units have appeal. But that doesn't mean imperial measurements didn't have their advantages.