system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Why not carry two lightsabers?

In the Star Wars universe we sometimes see people picking up a second lightsaber in duels, as for example at the end of episode 2 where anakin takes obi-wans lightsaber to fight against dooku or in some of the cinematics of the old republic. If you are a jedi or sith and feel like you are stronger in combat with a second lightsaber, why not carry two from the get-go? 

Some people do wield two lightsabers, even a padawan such as Ahsoka. Also, some are lost or destroyed in battle and need to be replaced, so it can't be that out of reach to craft a second one, can it?
gpt
Because not everything revolves around potential DPS. 

Those who do feel more confident with two blades - carry two blades, or a saberstaff. Some carry two saberstaffs even. Most jedi feel confident enough with one. When you're skilled enough, amount of blades won't matter.