The county coroner ONLY counts deaths when COVID is listed as the cause of death. The state includes cases where COVID is listed under "other significant conditions". The difference? The state total for Milwaukee County is 532. The county's dash board, which uses the coroner's standard, is 428. That is about a 20% difference. Extrapolate that nationally and you get about 170k deaths instead of 210k deaths. Of course, the 20% difference is made up of cases where arguments could be made one way or the other about whether the deceased would have lived but for COVID and the attending physician may have down played COVID for professional liability reasons (failed to diagnose timely, offer proper treatment etc.). But even excepting all 20% as having nothing to do with COVID, you still have a very large number of people dying from COVID. And if you add back all the people who never get tested and die at home or just after being admitted to the hospital, you probably break even or come out slightly higher.
For public health officials, this minor distinction is nothing that would for a second change anyone's approach to combatting the virus. It is still very dangerous even if you reduce the death statistics by 20%. That is because these outbreaks have a massive human toll that extends well beyond the few who sadly pass away from the virus. Hospitals fill, the quality of care declines, hospital workers are strained to their limits, and those who survive often have significant long term impairment.
https://www.postcrescent.com/in-depth/news/2020/10/01/wisconsin-coronavirus-hospitalizations-worry-staff-who-fear-surge/3574106001/