Enacting a lockdown is possible, but having the populace respect it - or enforce it otherwise - is another matter.
Besides, the worst lockdowns have only just begun recently. There are a lot of people who will go ahead with, say, a 2-week lockdown, but will balk at 3 months. The true test for the ability to maintain things that way is still ahead for Western countries.
It's just not so clear it's possible to do such a lockdown in non-Authoritarian, free, countries.