From a continental European point of view, I'm not sure if it's (just) the Saxons: it's more that the Vikings are just really rather popular!
They tend to get a lot of the screen time in shows, the focus in books and feature prominently in video games - they even have a subgenre of metal music named after them.
At least where I'm from, you rarely hear or see anything about the local boys, the Carolingians, and the few notable books or museum exhibits somewhat specialized on the topic tend to focus mainly on when the Vikings visited. Based on my limited experience at least.
All that is a positive feedback loop too of course. Specifically for wargaming, the figures that are expected to be popular may nowadays get some plastic sets from Victrix or Gripping Beast, which will then feature Vikings among their number, and as a result they are popularly played because you can get a large and varied army for cheap, or a SAGA warband out of just a single box. Meanwhile, Byzantines are only now becoming available through Fireforge, for instance the Dark Age Irish have a single sprue from Wargames Atlantic, and those aforementioned Carolingians should just be converted from Normans, if you don't fancy the available metals.
Not that I'm complaining, as, well, I do also like Vikings...