If lockdowns merely delay the coronavirus and ultimately there’s nothing you can do to stop it, then the enormous costs of lockdowns surely outweigh the scant benefits. From Jonathan Sumption at theguardian.com:
We need to think hard about whether the benefits outweigh the harm for young people and those struggling with mental health

Suppose there is nothing that governments can do to stop the spread of Covid-19. What then? It is not a hypothetical question, as England is discovering. “We’ve got to be humble in the face of nature,” the prime minister observed in Saturday’s Downing Street press conference. But humility learns from experience, and there was no sign of that in the measures he then went on to announce.
In my opinion, the problem with lockdowns is that they are indiscriminate, ineffective in the long term, and carry social and economic costs that outweigh their likely benefit
Lockdowns temporarily reduce infections and associated deaths. But they do so only by deferring them to the period after they are lifted. Members of the government’s Sage group pointed this out back in February. “Measures which are too effective,” they said, “merely push all transmission to the period after they are lifted, giving a delay but no substantial reduction in either peak incidence or overall attack rate.” In the meantime, these restrictions prolong the crisis, slow down the process by which the population acquires a measure of natural immunity, and cause immeasurable collateral damage. This is what we are experiencing now.