I could not say much about the state of jazz affair in scandinavian countries (as there is lot of new jazz coming from there) but as fas as Germany or Italy is concerned (I am ofthen there, in various places) jazz is not so 'popular' among 'younger' crowd. I spend lots of time in Berlin, there are few nice clubs where jazz is played live on regular basis, but the places are not that big and not really overcrowded (if anywhere else is different)
Even in Perugia, in Italy, the town which hosts second largest jazz festival in Europe (Umbria jazz) and known as university town, there are not much jazz going on, outside the festival times.
One should look at record sales to know for sure (or perhaps not, as everyone stream these days) to be certain, but looking at department stores, the classical department is always much bigger and with more customers, at least in ones that I have been.
Here is one link, my favourite and biggest record, book and movie store in Berlin. In fact the department with classical music occupies the whole floor, in the basement, biger than all the ohers combined. (click on the photo to scroll for more photos)
https://www.kulturkaufhaus.de/de/musik/vinyl