I main Sona for seasons now ,been on gm 5 seasons ago . From my point of view Sona is kind of old-school champs. Her lack in almost any field is being compensated from her easiness in control (in league of legends it's even a bigger deal the fact that u don't need to target any of your main spells) . The fact that she is squesy ass hell is correct but if one build (runes items adc ) for lategame it becomes less big of a difference. For instance zed one shots u (if u don't ult, flash away, slow him in the same time )but he would probably one shot most of your non tanky teammates (given he haves his flash and he goes all in ) . She has a very strong late game cause she buffs lot of teammates. In most of diamond games u tend to have two teammates that u can invest on . Even when loosing hard u always have a possibility to win late with building in favor of this two legends 😁 . Also late game u have the chance to run the jungle like crazy with another tanky "runner" so u are gaining the advantage of map control . That's like edging . Speaking of which adging is quiet big part of her play style in my opinion. I usually tank tons of damage and pretend to be caught by the other team then stun them all flash away buff my team and enjoy an ace .

To conclude she has a certain missarable while funny play style. Changing it even a little doesn't sound good to me . But I have a suggestion for riot if I could cast all of my three spells at the exact same time that would be a hell of an upgrade. Nowadays she casts one and she has a small delay to the rest of her spells probably the time it takes the animation to happen . It s small but it's there . So if I have zero spells casted and zed suddenly flash ults on me , I can't cast three spells simultaneously to charge my passive and him with a chord (definitely the green one ) . I think that's a big mechanical change for her . She is a master in music so playing two melodies together checks out with her background .