> What about people who didn't get tested?
That's not what's skewing the numbers. It's the inaccuracy of the test. The current nucleic acid test will return a "positive" result for any coronavirus, not just SARV-CoV-2. The opposite was true in China. Their test wasn't sensitive enough to return a positive result for people who were exhibiting all the clinical symptoms. Thus, the unrevised mortality rate within China is a drastic under-estimate.
This is why so many people are asymptomatic. In the US, the number of infected is way over-inflated. President Trump acted fast-enough to seal the border, so very few COVID-19 patients made it into the US. Most of the first patients were quickly located via contact tracing, and the subsequent lockdown has prevented it from spreading.
Don't believe any of the numbers, they're all bullshit. The numbers from China are bullshit because their government worked to suppress the truth, and the numbers from the US are bullshit because our testing returns too-many false positives.