There's currently among the healer jobs six spells that seem somewhat poorly put together when compared internally and against other actions in the game, mainly when it comes to level scaling.

Stone II/Stone III, Ruin/Broil, and Malefic/Malefic II are spells where the stronger spell in each pair is simply more powerful (MP per potency per GCD) but mechanically identical, invalidating the weaker spell when available. To the best of my knowledge, this invalidation of one action by another action is something that only exists among the healing jobs. It's a unique point, but perhaps not in a good way.

Would it not be better for the spells in question to scale with the help of traits, rather than having them as separate spells?

Scaling with the help of traits would mean that when playing level-synced, a player would neither have the need to move around spells or replace them, nor resort to macros currently created for this convenience. For console players, this may alleviate skill bar bloat.

A possible downside would be not having access to the weaker action when wanting to skirt close to a specific health level, as we're sometimes required to do in levequests. Though I cannot personally remember being in a situation with such dire need.

Currently the system does not appear to support traits to be added to a job, only classes. But since we keep class traits when having a soul crystal equipped, the implementation isn't impossible. Although it would require some shuffling around of spells and quest rewards, as well as changes to trait loadout and possibly new actions to replace the Lv 54 slot currently used by the offending spells listed above. The sheer amount of work renders this alternative unfeasible in the near future, but perhaps 4.X will be able to bring some bigger changes.

The question remains however, disregarding workload, would this implementation be better for us players? My impression is "yes", but I'm curious what other healers think.