What I was trying to say, it that it's the transition that's painful. Britain hasn't finished, they still use miles on roads and pounds for groceries. Canada has mostly converted, except that you have to deal with all the exports to the US and some grocery stores have converted back to quoting prices in pounds - $4.98/lb sounds better than $11.00/Kg - but they must weigh and sell in Kg, so trying to match the advertised price to the label is impossible.
50 years ago I was educated in metric and thought I would never have to deal with the arcane Imperial and obtuse American Customary units. Yet here I am still having to remember that 14.5 psig = 10e5 pascals, there are 2.2 pounds to the Kg, a BTU is the energy required to raise a pound mass of water one degree fahrenheit and is 1.06 Joules, etc. Not to mention just
what a pint is.
I see so many mistakes being made - especially since Americans use units that are dimensionally inaccurate - conflating mass with force, force with pressure - even mass with power: a '1 ton air conditioner' - really, a short (American) ton of ice melting over a 24 hour period - why is that supposed to be more understandable than 3.5 KW!
I am convinced my grand-kids will still be dealing with the mess.
