Direct comparison of perception of democracy by people who have lived in both countries would be much clearer evidence of differences in democracy itself.
However, the raw perception of democracy without any other reference to other democracies does not allow for comparison/measurement of democracy itself but rather indicates how happy individuals feel within their current democracy.
The data is a good story and it does encode information, but that information is more significantly influenced by culture, current events, and overall happiness of the populace than it is by “level of democracy”