Way back in ARR, Tankbusters came out a lot more often (some as often as every 30s) and Benediction was on a 300s (6 min) cooldown. It was more or less an emergency button and you could use it on average two times a fight at most. Tanks were also expected to swap roughly every 2 to 2.5 minutes in high end due to only having 3 mitigation cooldowns. This was also a time when WHM risked going OoM when sustained healing with Cure I, BRDs were needed during raids for TP and MP recovery and attacks could randomly Crit forcing Tanks to be topped off most of the time.
Fight design has changed so that most damage is avoidable and tankbusters are once every few minutes, Crits on most attacks have been removed, Benediction's cooldown has been halved and all cooldowns reset after a wipe.
Benediction started out as the WHM emergency button, but now has become one of the WHM's primary healing abilities due in part to a reduced cooldown length and lowered healing requirements.
Which is due to Fight Design and Job Design not aligning. Lilies were originally designed under the assumption that fights needed constant sustained gcd healing with ogcds being interwovent to cover the HpS deficit caused by increased incoming damage which would have been fine if fights required sustained healing of the level. Fights on the other hand had very spike heavy damage patterns which were coverable with ogcds, Shields, Regens and the occasional Cure 2 equivalent. The original Lilies were less relevant the fewer Cures a WHM casts and the player base figured that they didn't need any to clear content.The original 4.0 Lily design was such as disaster because casting Cure/II is not nominal. Lilies today are able to be used for healing-on-the-move mechanics because WHM has the least mobility in this game, not BLM. In Savage you don't have to heal all damage right away, it can delayed to weave from movement and this is where it's nominal instead of casting Medica IIs. Damage goes off, stand there and finish the Glares, then move into your clock position(s) for the next mechanics while weave the lily heal. You can actually get Misery gain in a fight like E11S because of all the healer movement and downtime.
Also a lot of the movement troubles and lack of weaving windows that the WHM suffers from is due to Glare's 2.5s cast time which leaves no time between gcds. Where as Cure's 1.5s and Cure 2's 2s cast times leave a fair amount of time for weaving between gcds.
Not arguing that Benediction isn't being put to good, proper or optimal use. Just that usage has changed from the intended form over the game's lifetime.
"Optimal use" and "Intended use" tend to be vastly different. Abilities the devs think of as mostly Emergency buttons and design fights assuming that they are not used often get messed up when players find optimization strats that use them. It often feels like the devs forget that the tanks each has an Invuln that can cheese mechanics.
Assize started out more as a once every 90s MP recovery tool that would also heal and deal damage.and one of those (Assize) is really more a damage ability with a convenient healing side-effect.
There is a phrase “It's better to have it and not need it than to need it and not have it.” The devs seem to design the jobs with this mentality.Plus, if I reserve Benediction as only an emergency panic button, 95% of the time I will never end up using it at all during a run.