Why didn't Luffy learn Rokushiki techniques?

One - Piece - Sound - Effects - Rokushiki Soru rokushiki soru Rokushiki Soru Tekkai Comics: Eisenpanzer) HAKI SKILL TREE: 'An unofficial skill ree of the different rokushiki soru Props to my friend who helped get soru Heres his channel! @UCdRT10fgEJIDisDcmuJoGpA

rokushiki soru Lucci's updated Vivre Card states that he's improved his Rokushiki I believe Geppo and Soru are applications of Haki that burn it internally