I'll go and try and be a bit more flexible in thought here and agree for a minute with some things that OP said. In terms of newcomers for certain big franchises, there's not much unique content left.
I mean yes technically Bandana Dee would have a unique moveset, but will likely borrow a lot from existing characters. A Kirby model, Peach Up B, Byleth F Air and B Air, weapon thrust D Air like Toon Link, and maybe some attack from the Kirby characters like Kirby F Tilt, Kirby N Air and Meta Knight dash attack.. it all would fit well. Bandana Dee would likely not be a high effort newcomer, but rather borrow from a couple characters. Impa could have this as well, a few moves from Sheik (aerials and tilts), Link's Bomb , Greninja's Shadow Sneak... Even Dixie Kong; unique dash attack, unique grab mechanics based of DK's, hair grab, Diddy Aerials, Bubblegum Popgun, Spinning Kong, unique stats compared to Diddy like less speed and weight, and again she'd be presented well enough. Toad is probably just as easy, Peach neutral B except using his own body, Turpins, a Mario Kart based attack working like Bowser Jr.'s Side B, a lot of Mario's regular attacks, and he'd function.
All these characters are key characters to their franchise however. And I think we should request them as "low effort newcomers" that take up 50% of a regular newcomers work, or potentially even less. Kind of like semi clones but with slightly more work done to them.