IMO our biggest error was conflicting information and guidance. Had everyone, from Trump down, set out clear, consistent, and simple guidelines for people to follow, we could have avoided lockdowns and had fewer deaths, not to mention far less political and personal contention.
We can say this much - whatever we've been doing so far has not worked. We should try something else.
Source: https://www.statista.com/statistics/1104709/coronavirus-deat...
Even single state figures are quite high: https://www.statista.com/statistics/1103688/coronavirus-covi...
The US state with the lowest death rate is Hawaii with 38 deaths / 100,000 (https://www.statista.com/statistics/1109011/coronavirus-covi...).
Compare that with Australia - 3.7 (https://covidlive.com.au/report/deaths-per-population) - Canada - 0.27 (https://health-infobase.canada.ca/covid-19/epidemiological-s...) - and countries with even stricter and longer-lasting lockdowns like Singapore - 0.00042 (https://graphics.reuters.com/world-coronavirus-tracker-and-m...).