The gas is the same. The additives are not.Apparently the US likes to have its own rating system and your 87 is European 90 - I think.
“Fuel in the US is really bad compared to Europe and the rest of the world” – is a very untrue statement. Fuel in the United States is as good as anywhere else in the world.
The additive package required by law in North America is not as advanced as what is available in Europe. It's based on standards from a decade or two ago (not sure of the time frame.) If you want the better package of additives designed for the latest emission controls you need to purchase "Top Tier" gas.