I mean he has never been stronger before. He has unlimited chakra,EMS, Rinnegan, Mokuton, Senju Dna, undying body and 100+ years of battle experience. Isnt prime described when someone is at his best?
So because he's Op he isnt in his prime... makes alot sense. Kabuto made him this way? True, but why does this change the fact that Madara has never been stronger before?
hes at his prime just because he has senju dna dosnet mean hes not at his prime, its like saying ohh naruto has kyubi chakra hes not at his prime, but madara actually had to earn the senju dna he fought hashimara to get his dna wich almost got him killed
Nope he was restored beyond his prime. So it's not his prime. But rather a different estance. You can say pervy sages died at 51 and he was in his prime.
So nope he's not in his prime and were not witnessing it.