Orianna provides shields, damage resist, buffs/debuffs, CC, and zoning for her team, and deals relatively low damage. She's an enchanter, cut and dry. She has team utility on all but one of her abilities.
Neeko has a root, and that's pretty much it in terms of team utility. No shields or heals for her teammates, no buffs or debuffs, no zone control. Her Q is damage. Her W is her escape/engage. Her passive is for her, not her team, letting her trick enemies into making mistakes or positioning themselves improperly. She's as much a burst mage as Zoe or Brand. She has minor team utility simply by the nature of being a mage and needing CC to be a threat, but she's nowhere near the levels of utility a mage like Karma or Orianna has. She is a burst mage. She's supposed to have damage.