She's certainly oppressive in lane. She adds a free 40 damage on one auto at level 1 of q, so one auto, q, and power chord reset auto will deal 200 damage at level 1 before damage mitigation and with only a spellthief's edge and no runes or masteries. That comes out to around a quarter of somebody's health at level 1. And that's not including if her ad attacks once as well, as that's another 100 damage.
And with level 1 fights, q aura adds a free 200 damage when adding all 5 people. In late teamfights she basically has a free talisman of ascension on her e, and a free locket on her w.
Literally, she is one of the scariest level 1 supports in the game, and one of the worst lane bullies because all of her harass is easy damage and she has near impossible trading power because of her w and e. And that's before her ridiculous ult and incredible scaling. Combined with the increased vision that trinkets have created, her lack of true escapes or cc before 6 is almost negligable as a trade off for what she brings to the table.