Sasuke didn't use any of the Paths because his Rinnegan was still new and he hadn't mastered it.
He used Deva, Preta, and Outer Path. How would he not have access to other three paths if Nagato can do so? I can agree on him getting used to the Rinnegan. But even then, they still can get countered by Naruto.
Madara didn:'t use them since his Rinnegan wasn't at full power in his Edo State.
Even if he was at full state, the only real threat to Hashirama would be Limbos. But that's it. I don't see how the other paths would do any better for Madara other than PS itself.
Obito didn't use them because he couldn't. He needed Duel Rinnegan to use them but he only had one.
Kakashi and Gai came to a conclusion that Obito already had spent chakra to control the Bijuus. It would be a waste to use the other paths since they have counters to them. Obito explicitly noted that Kakashi had good eyes after that.
It's not the level of Opponents it's the fact that guys like Sasuke and Obito don't how to use the Six Paths Technique or they can't use them.
Already addressed on Obito.
Sasuke was getting used to the Rinnegan. That doesn't translate into him not knowing how to use it. Especially given that he has Sharingan to copy the concept of the paths Madara used.
