I wouldn't say their obsessions but rather interests.
After some time, when I realize how much I have grown and developed and how much my intellect has increased, certain things I start to see differently when I used to enjoy them.
For example, I was highly into Log Horizon the anime. It looked promising, the main protagonist was an Intelligent and strategic individual. He seemed interesting and the story seemed to have me interested.
Looking at it now, boy oh boy have I been wrong. I am glad that I grew a lot more to realize that the anime was nothing special. It had used typical tropes,cliches,paper-cut-out characters,generic plot and an uninteresting and boring visual style. I just realized it was a generic anime that wasn't special at all and I could tell it was made with the intention of indoctrinating children due to how easy it was to spot what the characters were like.
I would say nowadays I am more realistic,have achieved more,wasted less time,require more intellectual stimulation,have a clear goal in life and I can see through shallow or generic works which would waste my time.
So I would say that the more intelligent you grow, the more you realize how pointless and how uninteresting some of the things you enjoyed are and the more you realize what really matters and sets your passion ablaze that you had under the radar.
The one thing I really enjoy more than anime and one thing that has grown is gaming. Gaming requires the skill,drive and intellect to succeed in competitively. It is also something unpredictable which I enjoy because I can expect new things. Gaming is always a surprise and is something that hasn't died down, if anything the fire grew more.
So I would guess certain types of Anime (Not all, I just enjoy the very heavy intellectual and philosophical types of Anime like say Psycho-pass) but I grew out of the light-heated shounen Anime's where the main protagonist is the good guy who always wins with nakama power. I prefer the more realistic and more interesting characters who are interesting and aren't perfect and don't use the Nakama power to win but rather use their skill and intellect to win (Death Note,Hell-sing - Hell-sing ultimate,Gantz (Awful ending which ruined it),Cowboy Bepop, Akira, Casshern sins etc.).
Also if its comedy it should be dark comedy since I really can't laugh at light-hear-ted humour because its so boring to me and it has its "gloves on" and is not witty or satirical.
To me shounen anime is like Micheal bay to movies. Very shallow,predictable,uninteresting and full of cliches and tropes coupled in with mediocre to poor execution.