All that’s being accomplished is reshaping the bell curve.
In the absence of a vaccine, that's all that can be accomplished from a public health point of view.
The virus will be generally controlled when enough people are immune that it cannot spread more quickly than the health care system can respond to those who will need hospitalization. People will become immune either through (a) vaccination or (b) contracting the virus and recovering from it. Since (a) is not available, (b) is the only option. The complication is to allow for (b) without overwhelming the health care system.
The hard reality is that large numbers of people will contract the virus, and in fact *must* contract the virus if it is to come under control; a minority proportion of those people, primarily elderly and those with previously-existing conditions that can weaken respiration, will become seriously ill even to death. None of these people should be written off but some will be beyond saving.
The purpose of quarantining, i.e. "social distancing", is to allow the best chance for the health care system to provide care for all those who must be hospitalized. While none of us want to contract the virus, it's false hope to think that quarantining is to prevent us from contracting it. The purpose of quarantining is to prevent us from *all contracting it at once*.
Do we really have to shut down the entire economy to accomplish that? I don't know. In theory if we could perfectly, selectively quarantine only those who would require hospitalization then we could let every one else contract and recover from the virus while continuing with their normal lives. I hope we will learn in a couple of weeks that we have over-corrected and can ease up on the degree of restriction we're now experiencing.
All of this is a temporary expedient until a vaccine is available, but for a vaccine to be proven, scaled up in production, and made broadly available worldwide (or even nationwide) will likely require months. Therapeutic medicines will likely be available more quickly but will still take time, and when available will primarily support strategy (b) above.