Britain does that too. They call it the 'metric pound'.
I live in Britain and I've never heard 500g called a "metric pound" nor just "pound". Probably because the imperial pound (454g) is still in quite common use and different enough that it'd be an issue. (*)
OTOH, the term "metric tonne" is quite common and only slightly different from the imperial (long) ton. Which, of course, isn't the same as the American (i.e. "short") ton that *does* vary quite a bit from the other two. That brings me on to something else... the traditional units that Americans use aren't even the same worldwide (e.g. the American pint is around 20% smaller than the UK one, fluid ounces are also different), i.e. the Americans' so-called "English" units aren't the same as the imperial ones used in England- or the rest of the UK- any more!
FWIW, pigs will fly before the Americans go decimal. Not my problem for the most part- I'm not planning on living there- but I do find it ironic that the Americans chose a sensibly decimal currency instead of adopting the "pounds shillings and pence" system (used in Britain before 1971) like they did with weights.
Though decimalisation only happened around five years before I was born, growing up in the 1980s, any remnants of that system I encountered (and hearing about it from my parents) seemed bizarre, confusing and anachronistic even then, like something from another age more like 100 years previous.
Admittedly, when you're 8 years old, anything even a few years before your time seems old, but while I understand most of the "LSD" money now, it still seems like something from another era, alien to me.
Anyway... I'm surprised that Americans didn't reject that Euro-socialist godless commie decimal system for their money and adopt LSD. How about it? Twelve pennies in a shilling, twenty shillings to the pound (240 pennies to the pound), guineas (one pound and one shilling), and coins like florins (two shillings), 2/6 (two-and-six, i.e. two shillings and sixpence), tanner (half a shilling), blah blah blah....
It was called "LSD" because you had to be *on* LSD to understand it. ;-)
So... since you all love your bizarre, non-decimal "English but no longer used in England" measurements so much, I'm sure you'll love Pounds, Shillings and Pence. And farthings. And thrupenny bits. (^_^)
(*) Ironically, according to Wikipedia, they do use that term elsewhere in Europe.