A quarantine approach might still be possible in some areas that are relatively sparsely populated, where there are only a handful of cases in community. There is one case in my county now and the public health authorities are indeed trying to track contacts, hoping to be able to isolate potential case areas and initiate one or more quarantines. The county is quite rural and has only a few large towns, with a total pop under 50k and an average pop density of around 30 people per square mile.
In more urban settings, once a few cases exist then it quickly becomes impractical to try to contain spread of the virus so it's down to mitigation efforts -- washing hands, avoiding touching the eyes, mouth, nose; and as you say, staying inside or at least maintaining ideally six feet between human beings when around other people, in order to minimize the virus being able to make the leap to a new host.
This virus often manifests with mild or no symptoms, so even if somewhat less contagious than other viruses, it makes up for that by its under-radar way of being able to infect without giving a carrier or potential recipient any heads-up about it.
The covid-19 virus is different to seasonal flu in a few ways, including what kind of pneumonia its severely ill hosts end up experiencing. This was a pretty good article about the details of what happens to the lungs of those who become very ill from this particular coronavirus.
Respiratory physician John Wilson explains the range of Covid-19 impacts, from no symptoms to severe illness featuring pneumonia
www.theguardian.com
Back on the thread topic, it's probably going to surprise all of us how disruptive the track of this pandemic will have been in terms of personal and economic inconvenience or hardship by time the virus yields to a vaccine or fails to thrive in enough new hosts to stay relevant as a public health threat. But it's clear from the scope of recent and official announcements about limits on public gatherings etc. that these are not responses to a regular ol' flu virus.
Weird in the meantime to think how many things we just take for granted (like production of new episodes of TV series, and the appearance in store shelves of our favorite breads and fresh produce not to mention the now notorious bottled water and toilet paper).