It doesn't help that a lot of these characters are clearly DC Comics archetypes that Hickman wants to play with, which makes them single-trait Captain Ersaztes, not single-trait originals.
It's also worth noting that Hickman has a poor track record for paying off his elaborate setups. Michael at these boards has noted that the "War of the Four Cities" in his FF never really happened, for example, and Secret Warriors ended with a set of last-minute twist that negated most of the plot up to that point. And the SHIELD series is apparently on long-term hiatus at issue #4 of the second mini, which was supposed to wrap everything up.
That said, I stand by my note that New Avenegrs was good; Secret Warriors got some great character stuff in as well, even after Bendis formally left the title. But yeah, other than those instances, both of which are otherwise swamped by the intricate yet hollow plotting, the majority of Hickman's Marvel work has been remarkably flat.
Of course, part of my dislike for Hickman's run might be based on the description of Secret Warriors by Tim Callahan
; "It's complex in a way that an Asperger's kid might tell a story". I don't know (and ultimately don't care because it's not my business) if Hickman has Asperger's, but I never felt like his work was the honest expression of someone who neurologically could only see meticulous structure without empathy. In some ways, I get the impression from reading Hickman's Avengers that it's cynically plotted and scripted to appeal to the current comics audience.
To whit: the character beats are there to remind the audience that these are the heroes we're supposed to like, and the big characters like Cap and Thor get the Jeph Loeb-style "grace note" moments with which we're comfortably familiar. The plot is structured so that it's part of a huge saga across multiple books, but the connections are extremely literal, and the call-backs are obvious ("One was life, one was death"). The plotting doesn't have any larger theme beyond the typical good vs. evil stuff of superhero comics (with even New Avengers ultimately being bad heroes vs. worse villains, at least the last I checked). It's got the meticulous long-term structuring you'd see from a writer like Alan Moore or Grant Morrison, but it doesn't have much connection to themes outside comics and Marvel, and there really isn't anything that would take the comics reader uncomfortable.
Since I am A.) on the spectrum myself, B.) not a big fan of those kinds of stories if they don't have characterization behind them, and C.) do my own comic where the empathy towards the characters is KEY, it kinda bothers me.