Did you read the entire paper you linked? The problems with it are numerous.
First of all, its not a study, its a summary report of other studies, hand selected from thousands (18,590) down to 24 for inclusion on their summary findings. It cherry picks by hand which studies to include/exclude, trying to pretend its purely scientific but their own bias creeps in all over. "We exclude studies that use cases, hospitalizations, or other measures." Cases and hospitalizations tie directly into mortality, so excluding them makes the impact of this report more dramatic in making the authors case. It also ignores that a large part of the "lockdown" approach was to "flatten the curve" so that hospitals don't get overrun, and the report ignores that important goal as well.
Second, the point of the report is to show that lockdowns had no real impact on mortality, but there are several problems with that assumption. The first is that any "lockdown" according to the report assumes 100% adherence to the spirit of the lockdown, but our own eyes tell us this never really happened. On day one, a sizable chunk of the population fought against and ignored any mandates, from masking, to restaurant closures, school closings, etc. The Fed never really locked down much of anything, except a very brief restriction on some international travel, which had no real impact for obvious reasons - it was too late, it was brief, it was not thorough. States and counties locked down some aspects, from schools, to restuarants/hair salons, large gatherings, mask mandates, etc, but again it was not consistent, it was far too late to stop all the spread, and even where there were mandates, far too many citizens refused to comply for various reasons, meaning the lockdowns weren't really lockdowns at all. There was no marshall law imposed.
The second problem is it purposely excludes pharmaceutical interventions and their impact on mortality. One specifically, Remdesivir/Veklury, had a large impact on reducing the mortality rate in severe, hospitalized patients. It wasn't available at the start of the pandemic but since summer 2020, it has reduced mortality vs no treatment considerably, but it's use intentionally ignored as part of this cherry picked set of data.
Bottom line is there are always ways to massage any data to show an outcome you want. This isn't a study with a control group, its a collection of data from other reports, hand picked to make a point. I could easily hand pick other data from other studies to make the opposite point, but let's use simple logic instead.
Let's imagine there are 10,000 random people gathered closely in a crowd, and you drop 4 covid positive contagious people into the mix. What would be the covid positive rate after 1 hour, 1 day, 1 week, 1 month, etc. Assuming no one had any treatment and no one isolated, the crowd stays together as a crowd and mingles freely as if nothing was happening. You would expect it would climb, and eventually almost the entire 10,000 would catch covid. Some portion of them would die from it, again excluding the impact of treatment which this report clearly does.
Now imagine 10,000 people who are entirely locked down in their house. They work from home, they have food delivered safely, they never join any crowds, they are truly quarantined. Now you drop 4 random covid cases into 4 random houses. What's the spread rate after 1 hour, 1 day, 1 week, etc. And what is the associated mortality rate?
The point is, lockdowns clearly, undeniably, conclusively work, to stop the spread and associated mortality, but lockdowns never really happened at all. There were some half assed restrictions, most of them were either ignored or had too many exemptions to be meaningful. Also there is no question that real lockdowns hurt the economy, which is why the Govt dumped several trillion dollars of borrowed money to reduce the impact. But that was never the question we should have been asking.
The question to ask is, how many avoidable deaths are acceptable to avoid hurting the economy? What number would you personally feel comfortable saying "thats OK, keep the economy flowing" vs what number would you say "that's too many dead people, maybe we should shut things down". Because that's the only question that really needs an answer. But saying the number out loud may not seem as easy as saying "lockdowns don't work".
