At first glance it is but maybe it isn't. All people behave more or less in the same way. We talk to each other, we buy food, we work in factories and offices and those places are the same the world over, we go to parties and restaurants. The virus doesn't care about national borders, it just transmits the way it transmits. I think it would be more surprising if the trajectories were wildly different from each other. The later reaction to the virus, how to deal with it, may reflect different levels of social cohesion when addressing a common problem and that seems to be more affected by culture.
There are enough principal differences between all these countries and how they deal with the crisis:
Start of the crisis (first infection case), different travel regulations, climate (air temperature and humidity), lockdown degrees, average population age, discipline of citizens to adhere to imposed lockdowns), testing volume, available hospital capacity, availability of masks and ventilators, etc.
The individual curves start to diverge at the end of the shown time axis. In the next 2-weeks segment, we may see more differences in the individual outcomes.