In certain kinds of stories, you want characters to have weapons. It's important: They need weapons to fight, their choice of weapon may reflect their personality, and it makes them look cooler.
The problem comes when you give The Hero a rapier, The Lancer a scimitar and The Big Guy a broadsword.
In real history, the development of swords in particular meant that each kind of sword had different [...] [tvtropes.org]