You're under the misconception that it makes sense for Europe to have a launch vehicle at all. The launches happen in French Guiana. The only reason why you would build it on the European mainland is as a jobs program for Europeans.
No commercial entity would come up with the idea of building a launch vehicle in Europe. Making a rocket reusable means that it would not leave French Guiana far behind. There would be less need for rockets from the European mainland.
> under the misconception that it makes sense for Europe to have a launch vehicle at all. The launches happen in French Guiana
Launch controlled by Europe. French Guiana is Europe, geopolitically speaking. SpaceX building rockets in Europe wouldn't give Brussels the strategic autonomy of an Ariane launched from below the equator.
No commercial entity would come up with the idea of building a launch vehicle in Europe. Making a rocket reusable means that it would not leave French Guiana far behind. There would be less need for rockets from the European mainland.