There is 1 slight difference between a Single player FF game, and this, that is that for this game you control a single character & have to deal with other players, playing their characters. I agree, if I played most other FF games and they had a shit story with bland characters & no real special things about them, it would suck, however in this game, unless everyone is on a level playing field someone is getting screwed. A special level such as what is suggested would have to be meaningless besides show, think if we already had that, SCH could only learn Embrava at lv100, but you had to pick it as 1 of your 3 "chosen" jobs. Every SCH whos lv99 would be screwed, while anyone(everyone who even so much as wants to use SCH for an event) at level 100 would be able to get in events, because they have Embrava.
Also you give a bad example in my opinion. In any group, some people are good at some jobs and bad at others, even if everyone were geared the same, all jobs 99, some people would stand out simply because they know the job better, or they play it better. I have lv99 BLU, my gear is sadly not far behind that of 1 of my LS members, yet he knows alot about BLU, hes good at BLU, I suck as BLU, even were our gear the same, I would never go BLU if it were between 1 of us being BLU, and the other being another job. The closest thing we have or need to specializing our jobs are merits, and even that should be removed because it doesn't work, its just a limiter that only lets us pick the good choices while the others goto waste, never to be used.
This is at least how I see it.