A recent episode of The Acolyte included perhaps the best anti-lightsaber weapon Star Wars has ever had in the form of cortosis, but it failed to explain why the Jedi Order didn't make use of it.

Like so many people, Christopher Ford and Jon Watts are fans of the Star Wars universe ... I think the way they did it in ‘The Acolyte,’ the crystal was exposed because it’s part a ritual ...

Lucasfilm plays Star Wars spoilers ... fun with them. The metal (not literally on the toy) forearm guards distinguish them ...