While I'm not against the lockdowns for covid, following this line of logic would justify a lockdown 100% of the time due to influenza, which is also a fatal disease spread by respiratory droplets. The hard question is where to draw the line.
I'd argue that the socially accepted response to influenza in the west is an awful lot weaker than it should be, however. People who have flu should be self isolating and wearing masks if they must be in public.