Level Syncing isn't the best solution

[Penthea]

Nope, just nerf abilities above the level of the dungeon.

This is all very well for dps, but what about healers? This change OP wants would either mess up healing or make some higher lvl healing spells completely useless as their mana cost would be higher for less or equal output. It wouldn't be great for tanks either if their enmity generation is nerfed on higher lvl abilities, thus discouraging them to use more than a basic threat combo.

OP's suggestion would only benefit dps classes. And benefit is a strong word to use because it would throw balance all over the place and make new players feel like their contribution matters less.

Yet, here we are, with Level 70 Dark Knights in a full Diamond Fending Set already in dungeon.

Having a cool outfit is not remotely the same as having three or four times the amount of abilities as a new player while in the same content.