There is a lot of discussion about mortality rates, population factors, population density and health systems around in this coronavirus, Covid-19 pandemic. Doubtlessly some are contributing factors but are they on they exclusively so? Their is a certain fallacy of some simple arguments why countries differ in this pandemic. That they differ is obviously not under question but why they differ is a very complex matter, on which doubtlessly many billions will be spent over the coming decades going to the best connected academics in each country.
Please see this paper for detailed analysis on mobility and influenza.