The premise of your argument is that there is a real choice between saving lives now and saving the economy. The problem is that without drastic measures the pandemic will overwhelm the healthcare system, many doctors and nurses will get ill and won't be able to do their job, as a result many young people will be affected because they can't be treated, which will overwhelm the economy itself. Saving lives now or saving the economy? It's a false dilemma.
Scientific research has shown that the US cities which were longer in a lockdown during the Spanish flu in 1918 recovered ecomically faster than the cities which tried to save the economy and lifted the lockdown a bit prematurely.