This way of building up resistance through widespread infection is often referred to as achieving “herd immunity”, though governments which practice the mitigation strategy tend to avoid public use of the term and sometimes deny that it is their objective.
Since the ultimate objective of mitigation strategies is to achieve herd immunity, whether this objective is admitted or not, social distancing tends to be encouraged rather than enforced, and is less rigorous, whilst mass testing for the presence of the SARS-CoV-2 virus does not happen, since it is deemed unnecessary.
The country in the West most identified with the mitigation strategy is Sweden, though it was also the strategy followed for a time by Britain.
And this really explains why this government is behaving the way it is doing. Is it incompetence, or is the pursuit of the policy to achieve herd immunity?