Experienced public health officials in 2006 warned that this would lead to disaster. Donald Henderson, for example, went through the whole list of possible restrictions, shooting them down one by one. 

Still, a decade and a half later, governments all over the world tried lockdowns anyway. And sure enough, since April of 2020, scholars have observed that these lockdown policies haven't worked. The politicians preached, the cops enforced, citizens shamed each other, and businesses and schools did their best to comply with all the strictures. But the virus kept going with seeming disregard for all these antics. 

Neither oceans of sanitizer, nor towers of plexiglass, nor covered mouths and noses, nor crowd avoidance, nor the seeming magic of six feet of distance, nor even mandated injections, caused the virus to go away or otherwise be suppressed. 

The evidence is in. Restrictions are not associated with any particular set of virus mitigation goals. Forty studies have shown no connection between the policy (egregious violations of human liberty) and the intended outcomes (diminishing the overall disease impact of the pathogen). 

You can forget about "causal inference" here because there is an absence of correlation of policy and outcomes at all. You can do a deeper dive and find 400 studies showing that the impositions of basic freedoms did not achieve the intended result but instead produced terrible public-health outcomes.