This might be true if American society as a whole embraced safety measures to keep the rest of society safe. That didn't happen. A significant portion of the country believe the pandemic was a hoax and took no precautions whatsoever.
On top of that, it's pretty clear by now that East Asian populations have some level of preexisting resistance to this family of respiratory viruses, given their proximity to past outbreaks of genealogically similar viruses. It would make sense that their totals will eventually be lower than those in parts of the world that haven't been exposed to SARS like viruses.