When Sanosuke was fighting, Banjin, his fists weren't fully healed and had very limited use of the Futae No Kiwami.
Anji can use the Futao No Kiwami with every limb.
If Banjin wore those newer gloves that Enishi gave him, the same gloves that he used against his final fight against Sanosuke, and fought against Anji instead, who would have won? Fight to the death.