One year ago today in COVID, Vox published an excellent article. It was later updated with fresh stats in mid March, but still a good summary of the consensus views at the time.
There was a lot of confusion in a couple of areas that persists to this day. First, there was the notion that "the whole point of 'flatten the curve' was to reduce peak hospital demand". While that's one important goal to be sure, the other goal is to reduce the number of people who get sick in total.
This graph is from the CDC, Trump and Birx used it in presentations. Note that the area under the flattened curve is much lower - far fewer people get sick in total, not just at one time.
Despite China shutting it down, Taiwan and Vietnam apparently stopping it at the gates, and South Korea getting a handle on their outbreak, the assumption of some experts was "we're all going to get it", i.e. 70%+ of the US population would be infected in 2020. (In retrospect, we performed poorly, but only about 25-30% of us got infected last year, and that's before vaccines had much impact.
This was a crucial difference in understanding, and in policy. If the virus could be suppressed to some degree, death tolls could be sharply reduced. If it was uncontrollable, all you could hope for is some degree of mitigation to make the worst of it a bit less extreme.
This also laid the groundwork for our post-lockdown failures. In the "we're all going to get it" school, once the ICUs weren't overflowing, it was time to open back up and get more people sick - roughly the Swedish strategy of a bare minimum of mitigation. It also fueled a lot of non-compliance. If you believe the virus can't be stopped and you're going to get it sooner or later, there's little reason to take action to avoid it.
These two schools of thought would drive much of the dynamic through March, and into the reopening wave in late spring.