I don't think it is particularly useful to describe certain societies as backwards (implying that others are forwards?). Instead we should look at how the Norse were similar to or different from their contemporary societies and not judge them as being on part of a gradient ranging from "backwards" to "modern".

To start off we need to decide what time frame we are going to use as our starting point. The "viking age" is a rather loosely defined and nebulous time frame. I personally take a quite Anglo-phone approach and mark it off as the raid on Lindisfarne to the defeat of the Norwegians at the Battle of Stamford Bridge (though perhaps going all the way to the failed Danish attacks shortly after). But that is a time frame of some centuries. Indeed at the start of this "viking age" the most famous viking expeditions and settlement remained quite far off into the future. Should we take the settlement of Iceland and the voyages towards Vinland as our standard? Or maybe the establishment of the Kievan Rus and their relationship with the Byzantines? The creation of the Danelaw in England after the Norse overran several Anglo-Saxon kingdoms? How about the reign of Knut the Great and his hegemony over most of Scandinavia and England? Any one of these time periods can claim to be the apex of the Viking Age. In none of these time periods do I think we can dismiss the Norse as "backwards" as compared to their contemporaries.

Scandinavia was not some isolated backwater with no ties to the broader world at the time of the "Viking Age". Scandinavia was a central part of the early medieval economic world and the rise of emporia as economic centers. Scandinavians were also heavily involved with trade with both the Byzantine and Islamic worlds, Islamic silver and goods have been found in burials in Scandinavia, and the famous Varangian guard is indicative of how deep the ties between Byzantium and the Norse were.

History is not a tech tree with a defined beginning and end with certain practices, beliefs, and technologies being "more advanced" than others. Norse society had excellent ship technology allowing them to embark on much longer and farther sea journeys, be they for raids or trading, and through rives, but until Christianity came to Scandinavia, Norse societies utterly lacked centralized bureaucracy or rule. Does that make them less advanced? I don't think so.

Dismissing the Norse as a backwards society because they lacked civil administration and monumental architecture, and other "hallmarks of civilization" is incorrect. The lack of massive stone structures that have survived to the modern day and the lack of a centralized bureaucracy early on does not make them any lesser than contemporary societies. There were many differences and similarities between the Norse and their contemporaries, but trying to shoehorn them into a specific label based on the achievements of their neighbors does them a tremendous disservice and overlooks all of the unique factors that made Norse society different from others.