Just at a certain stage of the pandemic, lockdown is much more effective than other methods, another question is that a lockdown that lasts too long after a certain point begins to bring more harm than good, and state authorities that impose restrictions on the movement of citizens should not forget that lockdown is a last resort, which should be used only in exceptional cases.
It is very difficult to draw a line. Many of the European countries hesitated to impose a lockdown for the second time, when the number of cases began to rise. But we know what happened in the end. The virus spread beyond all control and the daily death toll touched record highs. The purpose of the lockdown is to keep the pandemic in control, until the vaccination can be completed. And according to the experts, the impact of vaccination will be seen from this month (February) onwards.
Hopefully that impact is really reliable, the second lockdown is indeed in need to lessen the casualties as the damages not only for medical but also financial from each places that being iinfected the most.
Even the government tried their best to inform and to implement every known rules to avoid this virus, but since this is pandemic is new to everyone and there's no ideas from different sectors of medical experts, they are all trying to find solution for this not just temporary but for the best long term cure for this virus.