Ok... that's your opinion and I respect it, but for me, art isn't just all about beautiful things. I know we all have different perceptions of how we see art, but I think it's all about expression—expressions of people's feelings and perceptions. Not all feelings are beautiful, so the portrayal will really vary especially in the current era now where diverse forms of art exist.
Da Vinci came from a different era, and I think it would be unfair to compare a completely different expression of art. Face mask on Da Vinci's Mona Lisa is definitely weird—I mean it's Da Vinci's art so we totally have no right to do that to his art...besides Mona Lisa looks confidently mysterious so I guess there's no use for her to hide behind face mask.
And yes, I also want to see more beauty in anime, but we all have different views about what's beauty. For me it isn't just the absence of flaws, but rather the presence of confidence and acceptance of the insecurities which like I said, the FMC somehow achieved in the end.
(Btw, FMC is Female Main Character. I've been using it since then, so I thought people here kinda understand it by now..hehe)