Because Cortosis was supposed to be rare, and not particularly easy to work with. It's soft and useless as armor in its natural state.Why doesn’t every person just wear lightsaber killing armor during the PT, OT and ST era?
I mean seriously why not?
That technology worked so perfectly 100 freaking years BEFORE the PT it has to be super advanced by the time of Darth Maul, smaller, more powerful, lighter, thinner, cheaper!
Why the hell wouldn’t ObiWan, Qui-Gon, Yoda, Anakin, Mace, Rey, Kylo, Maul, Palpatine and Vader use it?
This show is THAT STUPID!