> lockdowns cause more deaths than they prevent
Maybe some people are arguing this, but certainly not all anti-lockdown folks.
The more compelling (and more subtle) argument is that Covid NPIs don’t save enough lives to be worth their high costs.
Contrary to most people’s intuition, the value of saving one life is not infinite — it’s something like the integral with respect to time of the happiness they would have had for the remainder of their lives (plus second-order effects like their death making their loved ones sad, etc.)
Since this quantity is finite, it’s in fact possible that making N people’s lives worse by x for duration D is worse than shortening M people’s lives by duration E, depending on the values of the variables involved. But most people refuse to even attempt to estimate the values, because human intuition (wrongly, IMO) tends to reject quantifying the value of life in this way.