This website is mostly wrong. It tells you 3.4% CFR for COVID-19 against 0.1% IFR of the common flu. Apples vs oranges. Flu mortality rates are mostly the same worldwide, this year's flu season was not much different to others. Higher in areas with no proper healthcare for seniors, lower in most other countries.

Flattening the curve means keeping R low, whilst raising the overall mortality, because the time of the wave is artificially enlarged. You keep the virus alife, esp. by closing the schools. The area under the wave is much larger with the flattening the curve strategy, even after several months it's not over yet. A normal wave is over after max 2 months. Politicians rely on people who cannot do the simplest math.