I dont why most of the espers are non meta, but in my opinion, maybe the developer hard to decide to make a balance for the esper because they need make more money form OP esper or new esper
In this case, Raven can be replaced with another AoE esper, to kill Ikki, and to fight Hilda, you can use Clara or Jin Yuyao to prevent her from sleeping. the most difficult thing is fighting toland speed in my opinion.