system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] Why don't any of the Jedi carry back up lightsabers.

I'm watching Return of the Jedi and it occurred to me that it would have been very helpful in many situations for R2-D2 to always be carrying a back up lightsaber throughout both trilogies. I understand though if it would have been difficult to Luke to get the resources for more than one. However, Mace Windu just hands Anakin and Obi-Wan some lightsabers in the arena in Clone Wars so they must have some just lying around and they don't have some Avatar/Banshee connection to their lightsaber. Those two seem to have a tendency to drop their lightsaber at least once a confrontation.
gpt
Historically, just handing out lightsabers like that is very unusual. It could be that those are lightsabers Windu collected from fallen Jedi, or perhaps his position in the order has lead to him having extra.  Most jedi's lightsabers are very personal to them, they assemble them themselves.