The problem with lockdown measures is that it will inevitably harm someone. We might all be healthy and safe at home so harm is reduced with respect to Covid, but what about the harm caused by the lockdown measures themselves.
Say you have a town of 100 people. If you went into a hard lockdown to prevent any spread, you might save 10 people from dying of Covid; however, the lockdowns caused 10 people to loose their homes, businesses, some committed suicide, some overdosed. The problem with this line of thinking though, is that it's impossible to quantify that sort of harm. You can look at how many people foreclosed on their homes or went out of business but that really only gives you a partial outlook.
So what do you do? In my personal opinion this is a no-win situation, with some things it's clear what the right thing to do is. In Covid's case it really wasn't clear at all. Do you lock down people to save lives from Covid? How much harm does the lockdown cause? Are the gains we get from locking down enough to offset the harms done by the lockdowns? Everyone will have an opinion on each one of these issues but there really is no good answer.