The issue is pretty simple. Regardless of people feelings, the damage formula is just simple math. You plug in the numbers and you realise that Noëlle, despite her 10 gajillion attack, gets left in the dust.

That's simply how it is. If you want a character that deals damage, Noëlle is far from being the best choice.
Now if you want something that you can just faceroll your way through Abyss, then sure, Noëlle is perfectly fine, and that might be well enough for you and there's nothing wrong with that.

But if you're seeking optimisation and efficiency, then you just don't Noëlle.

Is she memed on too much ? Yes, like Amber. Is she underrated ? Not really. She just fills a niche that isn't needed currently.