it isn't completely useless, it is mostly useless. In the sense RDM is good for really 2 things, Brewing, id say its the second strongest in the game no doubt, eiter chainspell brew, or Sang Blade brew, and of course outside abyssea, where enfeebles mean something, and refresh matters (looking at voidwatch mostly).
RDM enffeebles should be completely removed from that list, and replaced with a proper stance function, similar to DNC's Fan Dance/Saber Dance, SCH's LA/BA. Instead inversly supporting and nerfing frontline ability, and backline ability. The enfeeble spells should be scrolls, with the options at 99 (if) supporting further options with specfic spell categories, offering bonuses to any of healing, enfeebling, enhancing, and elemental. With the other 2 designed around Combat and Defenses.
Don't try and play little games with, Ive shred my fair share of ideas, and made my disagreement and agreements on others. Lots of times, don't sit there and pretend I haven't been rated to subdefault and back based on my opinions both shared and opinionated on.
The fact of the matter is, RDM in the current game is bad, really bad, while it is fun to play, it is not beneficial to other, and outside of fun factor not beneficial to your self.
You mentioned about me get 5:3 on my DNC, that is important, the faster I get sh*t done that I want/need to, the more time I have to @#%^ around on my RDM and farm dark rings, solo dyna currency, duo ancient currency, all stuff I also like to do that my RDM is great in. The faster I get done with mundane things like seals, and nm farms, the quicker I can go do other sh*t.
RDM is crap inside of abyssea, just deal with, the job is not designed abyssea friendly. Sure it might be able to play hero and get 3 procs here and there, turn some heads etc. But thats rare, and about the only thing RDM offers, all be it impractically.
No ive gone over the pro's and con's enough, RDM just has to many red flags in abyssea. It sucks, but I chose to level stuff that helps reduce mine and others time in abyssea, so we can do things we like to do.