I agree with that as precisely stated, but one can reasonably make subjective judgements (and indeed our politicians are doing so at the moment).

If we could live on average 6 months longer if we permanently stopped all gatherings, closed all restaurants/bars, and wore masks all the time we were outside our house, I think most people would say “screw that; it’s not worth it!”

It’s a subjective judgement rather than an objective calculation, but it’s still valid.