Not the only one, but probably a minority. Dual-wielding identical weapons is mostly a meme popularized by fantasy literature and games, and the movies and pc games based on those.

In actual reality people are quite bad at coordinating similar weapons and don’t get much benefit out of it. So the classical dual-wield is a bigger main weapon and a smaller supporting offhand, beginning with shields being used offensively (and getting smaller and more maneuverable with the main one becoming lighter and faster - see buckler) and ending with classic combinations like rapier & parrying dagger or Daishō (a katana & wakizashi pair).