Besides the economic harm and potential developmental harm induced by closing schools for kids, I think lockdowns did incalculable social harm to society. It gave huge swaths of the population a grudge against the system, a chip on their shoulder that won't go away anytime soon. It burned up goodwill and trust for experts and politicians (who generally didn't have much to spare in the first place.) And coupling this…
Many around my parts were being outright belligerent asshats when all we had was asking nicely that people distance and wear masks. A substantial subset of the population did the exact opposite, and caused all sorts of trouble being antagonistic even to people just trying to buy groceries.
Then the lockdowns happened and it was like a light switch. I rarely saw the same kind of troublemakers acting out that way in public. Apparently once the US starts gutting its own economy to deal with an invisible threat, people start taking it more seriously. Until then it was like they thought it was all fake news, running around mocking the gullible masked suckers.
But why they didn't end far sooner, like maybe once food supply chains were recovering and our shelves weren't empty anymore, is totally beyond my comprehension. It evolved from "flattening the curve" to "prevent as many deaths as possible at all costs", which IMNSHO is where it went all wrong.