Much like how the first Hokage deploys his wood-style and Sasuke deftly uses his darting glances, Naruto inheres the Ninetails in spite of his earlier fallout with his tailed chakra pal. So how powerful would he be without the Ninetails?
If you strip Naruto of Ninetails it would be a matter of consequence, but not nearly as much as you believe.
The important distinction here is that he still has his six paths chakra.
Allow me to draw excerpts :
Madara barely escaped after he was brought down with a Sage art Rasenshuriken.
This is all without Ninetails chakra, I should remind you.
Naruto’s six paths chakra gave a massive fillip to his chakra reserves, ninjutsu abilities and his taijutsu abilities.
Before his six paths chakra, Naruto could barely catch up even with a blind Madara in taijutsu.
This is Naruto charging with Sai only to get catapulted into the air.
Later on, with his six paths chakra, he goes on to fight six paths Madara pretty evenly in hand to hand combat. So obviously his power had increased many folds.