And healthcare workers/ carers out working? The petrol stations/ supply companies/ deliveries/ cleaners etc etc etc needed for any healthcare services to function?
People seem to think this is some kind of gotcha - but essential workers like that have been the ones allowed out in China.
Sure, if one of us here was to order a citywide lockdown, with no allowance for that, then it wouldn't work. But if it is ever done here (and I'm not saying it should be right now), then things like that would have to be planned for just as in China.
Other countries have had to do these things despite the very obvious problems they cause - they're not stupid and they're clearly not doing it lightly. That should tell us something about what an emergency it is for them and might soon be for us.