While I don't disagree that they are almost all designed poorly, they were meant to be designed with raids in mind specifically. Now we only have the 1 raid, but we have raids 2 coming later this year.
You would probably also say that debuffs are also useless anywhere but raids and record times. And you would be justified in saying so, but that doesn't mean that they shouldn't exist even purely for high end grouping content...
It doesn't help that they gimped the meta before it had time to take off. Aurora spells should atleast have a t90 version, if not being exclusively t90 in terms of damage.
Though I guess I should admit the seren spells/prayers could be given the niche value of allowing players to do personal challenge type stuff. Thats one thing I don't put much value into when evaluating the usefulness of certain releases.
I admit, invention has been great for players who do enjoy these personal self challenges, but for someone like me who doesn't really find enjoyment from doing those, invention has come off as a flop. The hardest content in the game was easy enough before invention, whether it was 5 or 6 person rago (the 50k hit before entering tells me he was aimed at groups of this size to defeat him
) or 10 person raids.
So maybe more specific stuff for the efficient try-hard type players could be good for Seren spells. I just personally don't think I'll find use in them as making Araxxi/Raids/Vorago easier at this point is just trivial to me!
Secondarily I guess theres value in reducing the learning curve for bosses too. While raids are easy for me at this point, it did take probably 25 kills or so to get a fairly decent understanding of everything. Not everyone has the patience to deal with failure and learning and become demotivated easily. So there is value for players to use potential seren buffs as they're getting acquainted with content too.
But still, ultimately I guess I just wish there was actual difficult content in the game, and not just needing to find ways to force the content to be difficult.