The other problem is that even within Europe, the really major outbreaks happened in countries which also didn't have widespread coronavirus testing at the time. For the most part they were usually only testing people who ended up being hospitalized. So the total death counts are probably reasonably accurate, but case counts are basically meaningless even for those outbreaks. (Which causes some problems when comparing the current, somewhat alarming case counts in many European countries with the initial wave.)
The US has 22% of the total (verified) global COVID-19 deaths. Most deaths occur in those aged 65 or above. 9% of the global population (702M people) is over 65. 17% of the US population (56M people) is over 65.
So the US has 8% of the population over 65 but 22% of the COVID deaths - it's still almost a factor of 3, so definitely not just reporting artifacts, but it's not a factor of 6+ either in terms of how the US is doing vs how you would expect.