Good points, but we still do not know how the second wave will look like in the countries that had quarantine (or in Sweden). We should revisit in a year. And there are other factors -- I personally know people whose cancer treatments were pushed out "because COVID" (for 1 and 2 months so far and counting). It is hard to quantify such things as there is no significant statistics, but lockdowns contribute to deaths, too.
> It is hard to quantify such things as there is no significant statistics, but lockdowns contribute to deaths, too.
There are systematic statistics on overall excess deaths which will include people whose deaths are a short term response to lockdown, so we can pretty conclusively say that lockdowns reduced short term excess deaths. They don't account for future excess deaths due to situations like cancelled operations you mentioned or different responses to a second wave, but they don't account for future deaths of COVID survivors where cardiac and lung damage caused by the disease is a comorbidity either.
Some of those cancer treatments would have been stopped whether there was a lockdown or not. Chemo becomes much riskier when Covid is working its way through the hospital.
