Absolutely. Everyone should self-quarantine when sick. Is it your sense that large numbers of Americans aren't doing this? Anecdotally, I haven't seen a visibly sick person, outside of my immediate family, in a long, long time (needless to say, I don't work in a healthcare setting).

Arguably, retrofitting every important building in the country to be well ventilated is a challenge on a similar scale to changing our deeply ingrained unhealthy cultural habits.

Not American (I'm in the Netherlands) so I wouldn't know, but looking at the graphs it seems like there are a lot of contagions happening.

I was getting take out a couple of weeks ago and a woman brought her coughing child to the restaurant, which doesn't seem great, so I have noticed people being less alert now that a significant portion of people has been vaccinated here.

>Arguably, retrofitting every important building in the country to be well ventilated is a challenge on a similar scale to changing our deeply ingrained unhealthy cultural habits.

Yeah, I hadn't looked at it that way, but that's indeed a big task.