In any team oriented game this happens naturaly, and if that doesnt work, its going to end up on straight max dps. It doesnt matter if its a lootshooter, moba or RTS.
Burst is generaly the most efficient system to deal damage as it negates healing potential. And also reduces chances on interupts. Even in an RTS this matters (where healing is effectively just building new units/saving resources).
The problem in ffxiv is simply that bosses are predictable. You know that after a certain mechanic there will be a few seconds of no action, which is a perfect window. There is rarely any situation in which mechanics can follow up (or its very static), and usualy those mechanics happen because its multiple smaller enemies overlapping their abilities (most of the time outside of boss fights).
A lot more things need to be randomized to counter this, but randomizing will be a problem in the highest difficulty fights (instead of skill it becomes RNG whether you can survive). This just doesnt sound right balance wise. A more difficult mechanic in an easier dungeon is often just bad. Still, static randomization can work (as in: you know that each time a mechanic happens, one out of 4 events can happen which all rely on diffirent timing), but again, its just learning patterns to know burst windows. Its not realy a major improvement here.
