There may not be zero tariffs in other countries, but the amount calculated by the Trump Admin doesn't account for them. It doesn't even consider them. It's as simple as "trade deficit by total volume". Unless you assume that, absent tariffs, trade would always be perfectly balanced (it won't be), then the difference is structural realities (such as certain climates growing things that can't be grown in the US).

They aren't reciprocal tariffs because the other countries don't have anything like comparable tariffs in place already.