Since start of the expansion, RDM is one of the few jobs which have fun and engaging gameplay which gets no complaints from players.
It is also one of two "turret" jobs of the game, spending rooted in place as much, if not more time than BLM that was traditionally so. It also lacks personal protection, mobility tools and is forced to melee by important part of its rotation and abilities.

Since design is solid, SE almost didn't touch the job since expansion.
By the way of gameplay, this is GOOD.

However, SE has made numerous "fixes" to almost all other jobs, often by the lazy way of potency boosts.

As a result, RDM has been steadily sliding into where it is now: the worst DPS job in game - even if by far not the easiest to play.
This is especially visible in current hectic / movement heavy encounters such as Barbariccia or new Savages.

To put it simply - RMD needs its potencies adjusted to reclaim its place, or it will face the Stormblood FATE: it will be perceived just as prog REZZ mage.