Not this again...

It is both clear and logical, let me point you to the relevant sections:

From the Class Reforms announcement:

Section 1, Item 3
Upper tiers of an action (such as Fire II and Fire III) will be abolished in favor of a system wherein potency and MP cost are scaled based on the player’s level.
Section 5
As mentioned under 1. Class-specific Actions, upper tier actions will be abolished in favor of scaling the potency of the base action according to level. The effectiveness and MP cost of the action will be dependent upon the level of your current class.
This may leave you wondering if a level 50 archer would cast cure with the same proficiency as a level 50 conjurer. This concern is addressed here:

Section 4, Item 4
All traits will be made class-exclusive.
Adjustments will be made so that certain actions will only unleash their full potential when paired with traits belonging to the same class.