I've seen a few complaints about job balancing, gearing/bis, and sub-stats. These complaints offer no solutions. I don't have an issue with balancing, sub-stats, gear, etc. but I've decided to create a solution, or at least, an alternative.
First, I would remove sub-stats from gear. A piece of Casting gear will have the Intelligence and Vitality bonus, but instead of Crit, Det, DH, or SpS, it will have a numerical bonus to each job that can wear it. In the case of casting, Blm, Smn, Rdm. The bonus to sub-stats is dependent on the job wearing the gear.
Removing the variance in gear sub-stats would make balancing easier as sub stat growth would be predetermined.
In place of sub stat based materia, I would change materia to be job specific, and by melding on your gear, it would increase that job's predetermined sub-stats while wearing this gear.
By creating materia specific to each job, demand gaps for different materia would decrease, as it would relate to job popularity rather than optimal versus suboptimal sub-stats.
One issue this concept would cause is other jobs sharing gear that is melded for another job within the same role. This will either incentivize players to only play one job per role type, or to acquire another set of the same gear type (casting, fending, slaying, etc.)
To prioritize players seeking alternative sets over only playing and melding for a single job, I would make a tertiary gearing method. Larger content like Eureka, Bozja, PotD, HoH, Criterion, could provide a time gated way of gearing like raids and tomestones.
While a tertiary gearing method might expedite the gearing process for those looking to gear a single job, it would also allow players to experiment with other jobs in high end content without having to worry about being under geared for their raid's skill level.
This was just an idea I had as an alternative to gearing and balancing, again, I have no issues with these things, just thought I'd share.