Combat speed buff if it is strong enough, like close to having a second pocket sprint, can actually be useful when it also apparently has a damage reduction component too. You can do some funny greed shit or some nice prog QoL with second sprint depending on the fight design. So I don't think it is unredeemably terrible it just looks boring in a trailer which is more the problem with healers, being boring not god awful in terms of power.
Btw for Sage fans/Ex-Sch players here I believe 21/26 of Sage's tooltips roughly translated. Don't look at potencies too hard, just focus on the general "what this ability do" factor. The main thing that this list is missing is what ability adds the "Eucrasia" suffix (in the trailer you notice a blue UI element turns on before the Sage puts a barrier on people) which creates your dot and any shield heal you generate, just think of it like Aspected Benefic/Helios difference between normal Benefic and Helios. "Icarus" is that dash thing Sage does, I don't believe it is actually like Aetherial Manipulation like this image says it is more like En Avant on Dnc I'm sure.