Lightsabers would be very impractical weapons in real life, and one of the main reasons is that the blade wouldn't have any weight, making it nearly impossible to swing it around without putting your own limbs at severe risk.

Are lightsabers practical?

In the Star Wars universe, lightsaber combat is a selling point. ... While this weapon is all-powerful and completely practical in both fiction and our imaginations, in reality, there are a number of headaches that would come with using a high-powered energy blade in contemporary combat.

Will lightsabers ever be possible?

It's possible to make a lightsaber, a physicist explains

Disney/Lucasfilm Exciting news for all you "Star Wars" fans out there — it's possible to construct a lightsaber, according to a physics professor from UC Berkeley. ... These tiny accelerators could be made to fit into the handle of a lightsaber, Muller said.