As things stand, most all jobs are balanced. I can't say for the most recent cutting edge content, the Final Coil of Bahamut, but you can take on any job and perform effectively in any content. Melee DPS have the highest sustained DPS, BLM is the king of burst and AoE, SMN has good sustained DPS, mobility, and some utility. BRD is often highly desired in raid content for it's support abilities. In most content, a mix of either healers and either tanks is sufficient.

Of course, with expansion time coming soon, we'll have to wait and see if some of these things will change. Take the RIP threads with a grain of salt, as we're largely unsure of how exactly the new abilities will impact the new meta, and it is mostly speculation.