I took a look at the cited paper. Table 2 was used for this graphic. It’s from the paragraph right above it

“Cars” includes “Cars, SUVs, pickup trucks, taxis, and mobility apps (like Uber and Lyft). The category also includes motorbikes.”

All 154 german cities in the data are listed as western Europe

First off “Africa” (22.2% cars) and “Australia and New Zeland” (75.9% cars) are not shown. But probably more important: The paper where the data is taken from used the traffic data from 794 cities, “weighted by the population of each observation”. Most probably there were more cities from regions with high car usage in the data.
Interesting side fact: “The 794 cities in the data are not representative samples of cities worldwide or different regions”.