The U.S. is doing many more tests than any country. Of course we will have more absolute number of positive case. All EU countries dropped their daily covid-19 testing from their highest daily testing numbers. Now only U.S. keep increasing testing. See the linked graph of Daily Covid-19 tests per thousand people. Let's take June 21 for example. On this day, U.S. did 1.54 tests per thousand people, Canada 1.02, UK 0.92, Italy 0.86, Germany 0.64, Finland 0.29, South Korea 0.21.
Link: https://ourworldindata.org/coronavirus-testing