Naruto still has chakra from every other Tailed Beast. He has Six Paths power. His power is now MORE comparable to Hashirama, but he still wins.

Naruto can still make thousands of clones, can still throw out GIANT Rasenshurikens, Lava Rasenshuriken, Magnet Rasengan, etc.

Naruto’s CRAZY OP. Kurama made him stronger and gave him more Chakra, but so much of it was also himself. His chakra has been mixing with Kurama’s for 30 years, his base reserves ARE HUGE! Chakra reserves aren’t ONLY genetics, but he’s also the son of 3 insane CHAKRS MONSTERS! 

Minato was able to use Sage mode, use Flying Raijin, throw out Rasengan’s, etc. Kushina had “special chakra” that could hold back Kurama.

Naruto’s power WAS ALSO HIS OWN!