I think some countries are missing here.

How is this always a comment? Of course, there are a lot more countries in Europe and the world. I suggest you search for a CSV file and create your own diagram. :)

Or one has to deal with the fact that not every picture includes everything.

Enjoy the data. 🍺

Because you’re biasing the diagram by deliberately excluding data. You could have excluded the best. Or the worst. Or some in between so two look close together but aren’t. Or it could look more uniform than it really is. Excluding data and not being transparent and upfront with is, is skewing things.

Oh god… of course that’s the goal.

The life-work-bias!

Your intention doesn’t really matter because it doesn’t change the fact that the visualization is intransparent.