Or jedi are still not very common and/or famous, so lightsabers are just seen as some old antiquated weapons. Thus, the stormtrooper may not assume that the one wielding it has magical forces that makes him a superior combatant.
True. But they’ve still somehow become more common in that scenario, if there’s a standard weapon against them. Could be for similar weapons like the dumb Darksaber things in TCW.