[RedDevil]

I am one foot longer than my wife, my 8 year old son already outgrown her shoe size.
For her foot and mile and paces are useless measurements.
For me they would be pretty much spot on, but as I am accustomed to metric I have to convert if I want to use them anyway, on top of that I am much less familiar with multiplying with 12 and dividing by 8 and so than with multiplications by the order of 10.
You can do halves and quarters in a 10 based system too. But unit conversions are no more difficult than shifting the decimal point.

Whether the decimal system is logical by itself is not the issue. We all use it.
A 12-based calculus would make imperial unit conversions easier, but even 'imperialists' use decimal.

The unit system you use will form your habits.
If cup is used as a measure sure enough most cup makers will make cups that match that size.
We have cups in all sizes, we take the one that suits the size of our drink (or thirst!) best.
Mugs tend to be 1/4 liter but not by definition.
When I cook I use the digital scale to measure quantities.

I won't say the metric system is better per sé.
I just want to state that when you grow up with it it is every bit as useful as the imperial system is to those who use that.
Making the changeover will require some getting used to, that is clear.
Two centuries after the change we still use remnants like the pound (homologated to 500 grammes) and ounce (raised 3½ times to 100 grammes). The 'duim' (inch) and 'el'
(two feet) got lost except in old sayings.

And yes, the meter is close but not exactly the same as 1/10,000,000 the distance from pole to equator, as the 18th century French scientists who did the measuring only had telemetry tools with limited precision.
That precision is irrelevant though; once metered out the measure itself becomes the standard. Just as has happened with other standards.

The point is that they tried to create a truly global standard to facilitate scientific correspondence and trade all over the world.
What better source than the globe itself? Pity it is so big, but hey.