Used a couple of US recipes recently and most of the ingredients are in cups, or spoons, not by weight. This is a nightmare to convert. Do Americans not own scales or something? What's the reason for measuring everything by volume?
You've completely missed the point, which is that most of the world measures ingredients (like flour for instance, where one pint is not one pound) by weight and not by volume.
Canada uses a mixture of imperial and metric, but not weights, so that’s an entirely false conclusion you’ve come to.
And that doesn’t help much, that’s only at sea level and a certain temperature, go do some baking with those exact conversions on a mountain and your cake won’t turn out at all.