Sasuke and Madara are the only Uchiha able to control and handle Senjutsu

[Kadmos1]

One wonders if Madara got/would get bored in wanting to learn and handle senjutsu by training. Thus he acquires and somewhat handles senjutsu by absorption.

 

[super michael]

One wonders if Madara got/would get bored in wanting to learn and handle senjutsu by training. Thus he acquires and somewhat handles senjutsu by absorption.

Madara was in a cave for who knows how long by himself and Zetsu, I really doubt Madara would get bored.