Why did the Vikings wear decorative swords that are useless in combat?

Scientists have found that the Vikings sometimes carried useless decorative swords that could not be used as a real weapon.
It seems rather strange that a warrior Viking could battle with a decorative sword, if it could not be used in combat. Why did decorative swords become popular with the Vikings?
For the Viking the sword was much more than just a weapon. Since the swords were complex, they were rare and expensive, and so they were not so common and used by kings and Vikings of high rank and class.
The Vikings believed that man and his sword are connected together. The sword gave power to the warrior, but the strength of the warrior could also be transferred to the sword.
This is also the reason that we often find wonderful stories about magic swords in many Scandinavian myths and legends. The Norwegian people were convinced that some swords were as powerful as the gods. Tyrfiding and Gram are two famous magic swords in Norse mythology.
The Norwegian legend about the hero Zygmund and the magic sword in the tree of Branstock, mentioned in Sigurdsaga, which is part of the Wolfgang Saga, show why swords were considered such unusual properties.

Some of the artifacts of the Vikings remain an unsolved mystery today. One such example is the Ulfbert Sword. This is an ancient artifact, far ahead of its time, and we do not know whose name is written on this mysterious ancient sword.
Not so long ago, scientists discovered the importance of decorative swords of the Vikings. A neutron diffraction study conducted on three Viking swords from the National Museum of Denmark showed that this weapon was created by means of template welding, a technique in which thin strips of different types of iron and steel are welded and then folded, twisted and forged in various ways for creating decorative patterns on the resulting surfaces.
All three swords refer to the ninth or tenth century of our era and come from Central Jutland in the place that is now Denmark.
According to Anna Fedrigo, a research associate at the Technical University of Denmark, this was the first study that allowed researchers to practically understand how Viking swords were made, showing how different materials were combined together.
The scientist says that such swords, covered with beautiful ornaments, became symbols of power and status, and they were almost never used, because they were never meant for combat. Since the role of swords has changed in the society of the Vikings, this “weapon” has simply become a decorative attribute.