Once infected by a virus its near impossible to be reinfected, so once we have had a large portion of the population infected who have recovered then it would become harder to spread.
The thing that is being done is to prevent a rapid spread which will strain the health system causing preventable deaths. The human race has no option but to eventually get infected if we are to better deal with it, HERD IMMUNITY.
because its new and we don't have a natural defense the fast spread of the virus is a major concern. We do have treatment which is not much more than hospital care for it like every other virus which also claims lives of people with underlying issue. Vaccine will be developed to help reduce the number of hosts that can spread it.
Not sure where you're getting that information about "once infected by a virus it's near impossible to be reinfected" from but it's not true. In addition to the fact that there've been an increasing number of documented cases of reinfection, the bigger issue is that the virus is continually mutating so even if we do find a vaccine by the end of the year it's entirely plausable that it won't have any affect on a patient because the strain of virus will be completely different. It already mutated between the first occurance in Wuhan till the peak of infection.
When looking at the 'herd immunity' .... gather you're suggesting that more and more people simply need to get it to build up resistance then I could agree with you to a degree rather than the herd immunity currently being talked about where very little is done to curb the hige rise in infected numbers. Would agree that this seems like the standard way when dealing with many such cases like chicken pox etc. Though not sure, becuause of mutation, whether this would mean much. And ... the costs in human lives we'd have to pay to get there
We do have hospital care. That's without doubt. But as you say we're looking to prevent a rapid spread to avoid the health system frmo crashing as we don't have enough sustainable care to treat the amount of patients that would come into hospitals without those current preventative measures that are taking place. We simply can't come off quarantine as we'll end up back where we started.
It's a hard one without doubt and I certainly don't know the answers. What I do know is that we're in for a very rough 3-4 months at least.