Forgot to say;
DR in isolation is for navigating on top of an 8/8 clound layer or over the sea out of sight of land when no other navigation information is available.
I can't think of anywhere in Europe where that applies for more than a few minutes when flying VFR in signt of the surface with no radio aids or GPS.
Therefore it is safe to say that in Europe even without any radio aids or a GPS one is still not going to use DR on it's own.
Perhaps that can clear up one of the biggest problems