Salthorae
Imperial Mountain Dew Taster
Yes, but...,Erm... Aren’t a paladin’s class abilities the “reward” for adhering to their Oath? Or I guess their subclass abilities. At any rate, I don’t think any additional reward is needed. To be honest, I don’t generally pay much attention to Paladin Oaths in play. I suppose if a Paladin committed a particularly egregious violation I might have some role playing consequences, which might lead to a sidequest for redemption, but I’ve never actually had that come up.
The point of the post is just that. DM's often penalize Paladins for egregious (or not) violations of the Oaths, but rarely for unerring adherence to them. Which to me undermines the point of them.
They are there as roleplaying guides for both the DM and Player. Think of them like another set of Traits/Ideals/Bonds/Flaws that can generate Inspiration if done well.
If you're willing to punish violations, then there should be room for rewards of well-played adherence IMO