The Wallace Sword (circa 13th century AD) , a 5.95 pound (2.70 kg), 5 feet 4 inch (163 cm) long two-handed sword allegedly used by Scottish knight William Wallace during the First War of Scottish Inde

Swords are much lighter than people think. Most were around 1-2kgs, and can still be quite the workout on your arm. 10s of kilos would have been absolutely exhausting, and probably pretty difficult to balance. That'd be a lot of weight suddenly pulling your center of gravity wherever you swung it.

A lot of common media used the weights of replicas from the Victorian Era that were thicker and more rigid because that takes less time and effort since they were meant for display. Sometimes they even included the weight of the sheath!