It is no longer possible that every infected person infects 2-3 people on average because so many have become immune; a person who is infected just doesn't have much chance to meet a person who can still get infected. The spread of the virus slows down or stops altogether. The transmission chains stop on their own instead of getting longer and longer. This is a rough and simplified explanation. I just wanted to point out that this number - whether 56%, 60% or 70% - is nothing unusual or difficult to compute. It is the so-called "herd immunity". It usually plays a role in vaccination campaigns: you don't have to vaccinate everyone, just a high enough percentage and the exact threshold percentage depends on the transmission rate of the virus in question.
Many of the numbers that we see are not scary in themselves because the disease is mild in so many cases or you don't even notice that you caught the virus. What is scary is the fact, that, depending on where you live, there may not be enough hospital beds and not enough hospital staff for anyone with any severe sickness if this coronavirus spreads too quickly. This will not happen if people follow the instructions that everyone must know by now.