Unless you are telling me he used PS for no reason. :lol Unless you are telling me that he didn't
I don't get it, when did it seem he needed PS to beat them?
- He pushed them to the max without it
- Gokage, already warn out with no PS in play, resort to what it seemed like their best combo
- Madara was about to get beaten, but busted out of their sealing attempt with
V4
- Stabilizes the chakra resulting in PS and swings once to show off its power (the slash did minimal damage and nothing to hinder the Kage's fighting capabilities)
- After that it disappears and Madara clearly states he won't use it again. Literally, remove the part he turns V4 to PS and it would've still resulted in Madara beating them, because PS did nothing to the Kages - it wasn't what saved Madara from the final combo, it didn't do anything meaningful to them to allow Madara to win.
V4 being close to PS in power doesn't mean he actually needed PS's firepower, only something strong enough to break out of the Kages' seal, which V3 wasn't, V4 was, but is still not PS. So no, he didn't need PS to beat them, nor did he ever say that - "time for me to
show you my full power". This is also supported by the fact that Madara beforehand let himself get Jinton'd to show Hashirama's face and lower their morale, while PS was meant to prove the massive difference between them.