Why should I play Eve when Galio is more reliable?

He has more damage, a faster combo, safer poke, more movement speed, better scaling, better base damage, better survivability, and stronger team coordination power.

Basically make Eveylnn's E deal 90%AP + 9% Max health per 100 AP as well as knock the opponent and all near by opponents up for 3/4 of a second, and give her 80% damage reduction while Q's followup is enabled. Oh, and for compensation her Ult deals 10% less base damage with 30% extra AP scaling.

Seems about fair.