happyhermit
Adventurer
Whatever you want to call it, the UAs don't have it. *shrug*
If it's "innovation", the UA have it. The Artificer is a fundamentally different class from what has come before, for an example among many. Many of the subclasses have particularly innovative aspects. The UA feats demonstrated innovation as well, they introduced new mechanics and completely new takes on old mechanics (making both dice matter with adv/disadvantage).
If it's "imagination" then I suppose anyone could claim that "there isn't enough of it" because that is pretty much a meaningless subjective claim. "More imagination" in this context (a game about imagining being in an imaginary world) is a pointless thing to ask for. More "strange" or more "dark" etc are almost as subjective, but they have some useful meaning at least and could be constructive.