Europe is no singular nation, but many nations, and so the numbers are given for individual states as well. The EU is neither a state, nor is it all of Europe. The federal states of the US are no nations, but parts of one nation.
Thats why.
https://www.worldometers.info/coronavirus/
Note that the table can be sorted and can be arranged what columns to show and what geographic parts of the world and whethersorting by high or low values first.