Where is the balance? Opening up too soon can result in much higher death rates because health care systems can become overwhelmed. Herd immunity is the ultimate objective but without a vaccine it will have to be done at a rate which will allow health care systems to cope, otherwise many will die who didn't need to. If fatalities remain in the range of seasonal flu, it is only because our health care systems aren't being overwhelmed. They certainly aren't in the order of seasonal flu in places like New York City, New Orleans, Detroit etc.
Even when government's do loosen up, will many people follow if they still see a threat to their lives? I won't. I think there will be some fundamental changes to society regardless of what governments do, at least until mass vaccination is possible.