Question i've always got : Rework VS New champions

Hi,

Here's a question I have always got in my head :

Why does Riot keep creating new champions whereas there are many that you need some updates ?

I think of champions having a very old gameplay or a kinda bad design and some others... i'm not making a full list, plus it's subjective somehow. It also concerns champions whom textures and VFX get old-fashion etc...

I mean, many champions could hope some gameplay/graphical updates (Ex Ahri's VFX that never got changed, it's getting old fashion). Why don't we have that instead of always new things.

Yes it brings less money, though Riot is not a poor company trying desperately to save their turnover each year, and I think instead of "Always more new buyable things" I would prefer a better maintenance of the old content.