I won't take that statment at face value, considering the fact that aging has show itself to be vastly superior to pochita and that is when it is actively holding back since it wants pochita to eat itself
That's because Aging is a devil with the name of a Primal Fear and Pochita is just feared on that level. It's pretty clear that they are relative is physical power, the only thing aging is superior to Pochita in is his hax, which does not account for a contest of strength.
It's weird because on one hand, Fami's scheme would be
really dumb if after she started the Chainsaw Man Zombie Apocalypse, Pochita and Yoru still weren't Primal Fear level when they're supposed to take on
Death.
On the other, Fami could've been leaving out some details to Nayuta when she said Yoru might be able to be made to fight Death. And Nayuta came to the conclusion Fami was trying to make Pochita and War more feared than Death on her own, so she might've missed the bull's eye.
On the other-other hand, Gunshy's totally right about this statement-
I'm sure what Fujimoto did for that statement was completely intentional, considering we didn't even know the Aging Devil or if he was even a Primal Fear at the time.
There's no point in namedropping "aging" with regards to fear level, and then revealing the Aging Devil is a Primal Fear, if it was just for a "Sike, gotcha! The statement was wrong!" later. Like, why even be that specific to begin with?
On the other-other-other hand, Pochita being physically superior to Aging, and Aging only having hax over Pochita is still sorta weird, because then that contradicts Yoru's statement about her strength- not power but
strength- being no match for Aging Devil's. And while Yoru could just be stupid (very likely honestly), it seems like Aging deadass created its own separate world that isn't a mental construct, but a physical place, as Devil's can be puked up in there and blood from the tree people heals Pochita in reality.
TL;DR: Gunshy's got the right idea in waiting for Part 2 to end to see what's up.