Why does Merkel’s explanation of the virus “R0” (basic reproduction number) work so well?

She makes abstract mathematical concepts very tangible. Instead of talking about R0 being 1.0 or 1.2 and the resulting number of patients, she explains:

• If that ratio is 1, it means that every patient infects one other, hospitals are full in October

• If that ratio is 1.2, it means that out of 5 patients, 4 infect another one each, and one infects another 2, we are out of beds in July

No graphs needed.