Just like a tiger demon, after transforming into a human, it won't gain greater strength; instead, it will weaken its inherent physical power, and the way of fighting will be greatly unsuited.
It's like making a normal person switch from walking upright to crawling like a snake on the ground. How could that improve efficiency? The body structures are entirely different, so naturally, demon races can't be expected to adapt by transforming into humans.
As for the idea that humans are Innate Spirit Bodies, so demon races must transform to advance further, this may exist in other worlds, but not in this one. Instead, cultivating with a demon body is faster.
"This is indeed a big problem, inherently too disadvantageous." Gu Shanhai can actually resolve it; he has the 36 Transformations and 72 Transformations, only needing some modification.
