Does Hwei lack damage? What exactly does he do that others don't do better?

Before you come at me with torches and pitchforks, this is a genuine question. I've been playing Hwei for a while now, but ever since I discovered his Blood Moon skin, I fell in love and have been playing him a lot more (basically every day for the past few weeks).

I've noticed he has more impact in the early game with Ludens, but in team fights, he seems to shine more with Liandry. Despite that, his overall damage feels lower compared to other mages.

I understand he has good area-of-effect damage, but even in games where I'm the sole AP source, it feels like he can't deliver enough impact in terms of damage, especially when the enemy builds health and magic resist.

My usual builds are Ludens + Rabadon + Magic Pen + Zhonyas, or a DoT-focused build with Liandry. I haven’t tried Ludens + Horizon Focus yet, but I’m considering it.

As a former Syndra main, I know my damage expectations are high, but Hwei doesn’t seem to turn team fights like Orianna, deal with frontlines as effectively as Cassiopeia or Vel'Koz, or provide utility like Malzahar or Lux.

I get the impression that he’s a “Jack of all trades, master of none,” dealing moderate damage in team fights with a quick spell rotation, but even in that role, there seem to be better options in this departament.

So, am I crazy, or does he really need a buff?