Isn't it interesting how in a lot of futuristic scifi, there are still conventional firearms that are available or used as a cheap or ultra reliable backup solution?
Babylon 5 comes to mind as one example, where most everyone uses PPGs (pistol like energy weapons) but its brought up how private security forces still often use "lead slingers."
Another example is the newer 2000's era Battlestar Galactica, where the ships as well as virtually all small arms fire essentially conventional ammunition, even by today's standards. Obviously there are improvements, but at the end of the day there's a chemical explosion sending a piece of metal at high speed toward the enemy. This is particularly interesting since the original TV show had energy based weapons both for ships and small arms.
As always, military forces will be pragmatic when it comes to weapons selection, factoring in cost, reliability, maintenance needed, etc. I believe in the real world we'll be seeing both a gradual rise in energy based weapons as they improve, while continuing to rely on time tested "throwing metal bits at the enemy" tech for centuries to come.
P.S. For anyone that comes up with an actual, no joke, exactly like in the movies, self-contained working lightsaber, I would be willing to part with nearly all my worldly possessions for that. Sadly such a device would violate several basic laws of nature as we know them today, but I can dream.
RE: How Laser Weapons Differ From Plasma Weapons