Warning: My inner political scientist comes out in the following commentary.
Easily satisfied or ignorant or misled or ...:
Roughly half or more in all 10 nations also think the EU promotes democratic values, with the French and Germans especially likely to hold this view. [Source]
Obviously, democracy was not clearly defined and neither was the term "promotes." One can promote something without being it.
To be clear, the EU is a technocracy, not a democracy. Those who hold with an utterly extreme definition of democracy as encompassing the most indirect and most hierarchical "representational" system designed the question.
If you look at the survey's Appendix, you'll see that the difference is not lost on the survey designers. Unfortunately, they didn't translate their understanding into the survey so respondents could qualify their views on democracy or establish their education concerning the subject. It was simply assumed by party affiliation. I count that weak methodology.
I'm assuming all the questions were included in the post reporting the survey results so one can determine what wasn't asked. Questions concerning views on elitism, direct versus representational, and "promotes" democracy at the EU-governmental level internally versus globally should have been specifically included.
... one should bear in mind that question wording and practical difficulties in conducting surveys can introduce error or bias into the findings of opinion polls. [Source]
All of that said, PEW RESEARCH CENTER is typically worth checking.