AP Sona's match history refutes this, He's very good at Sona, and that's one of his top champs.
If Sona is so bad, then why does Xpecial perform better with Sona, than say Nami or Zilean? And you say Nami is much much better than Sona.
Third, statistically, A Wild AP Sona is no longer the best Sona player in the world. He might be second best, and He's only Diamond V, he's also only played 2 champions since the start of the season
and plays those two champs religiously (Lux and Sona). His performance on Sona is much better than his performance on Lux.
Fine, whatever. Sona's rework was a disaster, but her kit is overloaded with Lich Bane. Revert to 4.12 and don't give her an auto reset with Power Chord reset. Bump the move speed too. Fair?
But she is hard to balance, do you understand me? She's godly in lower elo, and awful when people know how to play around her in higher elo.
Oh yeah, I think that Blitzcrank fits this archetype perfectly. In high elo heck in Silver, people just position themselves so that they won't get hooked or they infinitely kite him out when he gets his only mine speed boost until they pop his only mine shield. Not to mention his speed boost also has a slow attached to it and his hook costs a shit ton of mana and he will run OOM with 3 hooks and is on a yuge cooldown. Yeah it hurts more, but the cooldown is significantly higher at 20 seconds at rank 1, with the all but likely potential it will miss. Unless Sneaky hitboxes kek.
Bottom line is this, Sona is indeed playable. Xpecial and Aphro played her last season. With 50-50 success.
At least she wasn't Diana'd like where her winrate dropped by 13% in all elos. It was impossible to detonate Pale Cascade. And her laning suffered due to the Crescent Strike base damage nerfs.
She isn't post rework Evelynn either, keep in mind that it took Riot over a year to fix her.