I disagree. I feel the root of the problem here is the job specific eso gears. Remove that, and there is much less of an issue because people then can switch around much more easily.
Of course, in a perfect world, SE would be able to design varied and interesting encounters that are perfectly balanced for a wide variety of very different jobs of each roles. This is not a perfect world, however. So if we push too hard for balance, that would only result in either homogeneous classes, where every classes is more or less the same with a little bit of gimmicky unique identifying trait (see AST) or encounters that would feel very similar.
As in, they would need to follow a strict checklist when designing encounters, where each one must have something that plays to each class' strength and nothing where a class perfectly counters the mechanic of the fight. So, cannot have magic only fight (pld will be left in the dust) or phys only fight (pld will be too op), even when lore calls for such a fight. Cannot have a fight with too much movement (what about blm?), too much raid-wide damage (whm only pls), etc. I think this would only lead to boring fights that all feel samey (or, boring jobs that all feel samey). This is also not sustainable moving forward, as more jobs are added, the constraints and/or balancing act would only get worse and worse.
I would rather have both the fights AND the jobs be varied and interesting. And if that means that some jobs are quite a bit better at some fights than others, so be it. Of course, nothing as far as rendering a job completely useless like making ifrit completely immune or even absorb fire damage. But at the level of AST for a1s or a2s pre-buff is okay in my opinion, it is definetely still possible to use that class in the fights, everyone may just have to work a bit harder if they really like the class and want to use it anyway. The key here is that there should be other fights where they shine, a class cannot be bad in all fights.
FFXIV is already in a unique position to be able to deliver on the above. We are not locked into playing just 1 class, like in other games. It only needs a slight tweak to make this possible:
- Make sure that the raid-relevant gears for a given role is shared (so this means that mnk, drg, and nin should share a gear set).
- For weapon, I guess they should stay separate, but perhaps give discount for 2nd purchase of weapon for the same role group.
- Give extra armory bonus for each class at the same role that you have withing the same role. For example, leveling the 2nd tank nets you additional 25% exp boost, and for the 3rd is additional 50% boost, etc. (sch/smn complicates this, but I think they are destined to be the only exception to the rule moving forward anyway, so lets just ignore them).
- rework glamour so that they are tied to the job and item, instead of just to the item. I already hated how when I make a glamour for my pld, my war is "forced" to be glamoured the same way. This needs to be changed so that I can glamour them separately, even when they are wearing the same thing.
- AF gears can still exist, but more as a starter gear (it being the law tome gears would have been perfect) and later on for cosmetic only.
So for those hardcore players chasing whatever-first, they would need to make sure they are flexible enough to be able to play all jobs within a particular role at a very high level, so that they can optimize the fight to the max and beat them at very low ilvl. This is probably an interesting exercise of min-maxing for them anyway. For more casual groups, they can afford to let their players play their favorite classes and wait out until they are sufficiently geared to clear. PF will of course be full of people demanding only the most optimal party composition AND overly high ilvl, but not like it hasn't already happen now.
I feel rather than trying the imposible to try to balance every class and every every encounter perfectly, this is the most viable way going forward that would please the most people.