With a two-week asymptomatic incubation period, there is basically no way to eliminate the disease just by sheltering. It's impossible to enforce that every person in the world self-isolates for 3 weeks, so as soon as we "return to normal" it will come back.
The strategy is basically, in order:
1. Reduce the rate of transmission to avoid overwhelming hospitals (which would increase the fatality of all other illnesses/injuries). When we have no reliable testing infrastructure, the only action we can take is sheltering-in-place as much as possible
2. This buys time to increase medical supply chain capacity and stockpile necessary supplies. This increases the amount of cases the system can handle, which is important when the public policy feedback loop doesn't see new cases until they're in the hospital weeks later
3. At the same time, build testing infrastructure to detect infections before they turn into uncontrollable outbreaks. This will hopefully catch cases before they get to the hospital, shortening the public policy feedback loop
4. At this point, we should be able to resume some moderate amount of activity without being completely in the dark. We will likely see a cycle of one week on, one week off, two on, two off, etc as we see how much we can control the rate of spread. This will increase herd immunity, but
will likely require months to spread the infection without overwhelming our health system
5. All throughout this time, high risk populations will have to isolate as much as possible, since they cannot be infected safely. Medical companies will be working on a vaccine, but it will probably take closer to a year before they are ready for the market.