Ok, here's where I step in.
Outside of personality, there is little that separates Daisy from Peach. She was created to be a palette swap and fill the same exact role Peach normally does, but in a different land.
And for the longest time, that's all she really was; a palette swap. And then they decided to spice up her personality just so there's at least something special about her. And she still carries out the same roles as Peach in all the games she's in, so it's still basically just she's a tomboy Peach.
Even Rosalina, who looks more like Peach (but from SPAAACE), is much less like Peach overall considering her powers and roles within the series.
Waluigi? He might be "Wa-ified" version of Luigi, but that doesn't make him a "Purple Wario" in the slightest. Right off the bat, he's made distinct from both Wario and Luigi in terms of personality, design, and other traits and characteristics. He never had that transition from being "the exact same as someone else" like Luigi and Daisy had.
Is he the most fleshed out character in the Mario franchise? No. But to claim he is or has ever been just a "Purple Wario" is sheer ignorance.