it is not a goal when it comes to fighting this war.
the goal is to contain and control the impact of virus, in the short term and long term, via many measures co-currently, such as adequate health care system that can cope with surge in demand, treatment that are effective and can reduce fatality , social distancing and hygine that slows down the spread, vaccinations that is effective with minimum side effects, and hopefully one that can keep up with the likely virus mutation .
herd immunity works for some virus while it doesnt for others, it takes a large population , some 40%, some 80-90% of population to get infected in order to develop herd immunity . As for now, scientist do not know what is the required infection rate in order for herd immunity to work for this virus. vaccniation is the safer way towards this than natural ways. Getting large population purposely affected for the reason of getting “herd immunity “ at the same time will come at very high cost of fatality, economic impact as people are unfit to work, expose vulnerable groups(the old, the children, those pregnent, those with high risk heath conditions in developing severe symptoms), and crush the health care system, leaving social, medical and economical trauma.
what countries are doing is indeed trying to “flattern the curve”, buy some more time, to get ready for the next battle. It is going to be a long war, many battles ahead. Scientist does not know this virus enough for the moment, as usual for outbreaks it normally takes years to understand the virus.
it is a scientifc concept, it is not a strategy. it may end up being a result , but it is not the first card a country would bet on, not with its people’s lives on a bet. You don’t give in immediately and turn in more than half of your people in the beginning of battle, hoping you will be spared your life without even knowing who your enemies are and what they would do to your other half of troops after surrendering. You fight, wait for re-enforcement, build up your army, refine your strategy, preserve your resource, negotiate, and fight again to win the war.