Perhaps this is too broad of a question but it seems somewhat odd that the sword, a sidearm, would become the dominant symbol of fighting in the western world. Can anybody explain when and why swords have so much lore and prestige surrounding them?
I answered a similar question previously in this sub. But to add to the point of my original comment, I think you need to re-examine the premises of this question. There are plenty of accounts of medieval soldiers using swords as their main weapons rather than a polearm. Medieval soldiers used all kinds of implements for "significant fighting," without feeling the need to sort everything into some kind of video game loadout.
A similar question, what's so special about a sword except its financial cost that would explain the cultish romanticism around it?