Sasuke wasted chakra for three days and yet his chakra is inferior to Naruto's. Obito was completely destroyed, but then he became the Ten tails Jin. Plus, the Ten Tails did most of the job after the revival. Obito only did well against Naruto and co using the Bijuu. After that, he didn't fight much until he became a Jin.
But yet again, physical energy is what I count as chakra reserves.
Sasuke used all the chakra of the bijuus, but as an Uchiha he didn't have the physical energy to keep going like naruto.
The juubi didn't help for anything, did you forget the toll it took to control it?
Why do you think mokuton was involve?
The juubi/Gedo mazou feeds on life force, that was the whole point of Infinte tsukyomi.
Controlling six bijuus all simultaneously drains chakra not support it.
Nagato had a hard time control six dead bodies for pain, six bijuus is a death sentence.
Physical energy is not chakra reserves, Justus that require physical energy take a good portion of your life regardless of the quantity of chakra you have.
Because Nagato has a massive amount of life energy, he can rinne tensei a whole village.
Madara/Obito can only bring back one person because their life energy are not as vital as nagato's.
Senju DNA helped Obito a bit