As someone that mains Sona and has since Season 3, I've felt her pain for what will be 5 Seasons now. She was gutted for the longest time and even when Ardent Censer broke all Enchanters, she was still not a staple pick. Now that Aery (and by extension, Sorcery with Domination off-tree) has caused her to see such a huge power spike and playrate increase, I get the eerie feeling Riot is going to gut Sona again before they look at the runes.
Aery is currently the problem, not Sona. Sorcery doesn't offer any better alternatives since Arcane Comet has way too little reliability and Phase Rush is no good on most poke mages like Sona. Electrocute is whatever; same problem as Thunderlord's Decree in that she can't proc it with her Q-auto-passive anymore. Her only real other option would be something like Kleptomancy (which, actually, does synergize well with her Q + STE), but the Inspiration tree is otherwise very mediocre. (The TotalBiscuits are alright, Hexflash sucks, and the rest of the tree is forgettable. The +5% global CDR one is good, though)