Even the English don't use the "English" system anymore.
Or the Scots, Welsh, Irish.....
And in fluid measures we never did. US fluid ounces, pints and gallons are wildly different - a US gallon is about 80% of a UK gallon. Actually we are an odd mix in the UK - by law weight and volume measures are metric which means I buy a container with 2.272 litres of milk in it, i.e. four (UK) pints. I buy fuel in litres (at about US$2.12 per litre) but express fuel consumption in miles per gallon even when living in a completely metric country where distances were kilometres and fuel in litres.
Speeds are invariably mph - and there will be chaos when they change the signs as some idiots interpret these as mph speed limits.
People's weights are in stones and pounds (1 stone is 14lb). My weight is 84kg but I did have to resort to a calculator for that.
Temperatures may be either. I tend to use metric units, but have to translate for those over 55 or aged between about 35 and 42.
When I was at school we were going to go completely metric (This was 40 years ago - long before the UK became part of the EU) but were taught both (sorta). Then this plan was dropped owing to the universal hostility of the retailers. Then it was picked up again.
My passport says I am 1.76m high, I say I'm 5' 9". Metric heights for people are just not meaningful for me despite everyone around me using them every day.
So the picture is far from clear. Imperial (They would certainly never be called English here) measures are still in very wide usage.