At first it was because I had panic attacks and anxiety - while metal itself feels pleasurable and good to me, it is a thing that activises, arouses, agitates. Makes your blood pumping. If you're having trouble with your nerves and anxiety stuff, that does not help.
But that was only temporary - it's more like... dunno, I was fascinated by other stuff, I returned to prog rock (where I started originally), listening to folk music (the folklore one, not the Pete Seeger one), opera, really old music (including chants) and classical and so on and I found out I'm not replaying metal much. Many bands that were always the constant "safe harbour" I had overplayed to death (Maiden, Dream Theater, Kamelot, even Opeth) and so I kinda drifted away.
Something clicked about a year and a half ago and I became once again obsessed with power metal - the one that I listened to when I was about 12, which I left behind for being too simplistic and naive and cheesy and silly... but it actually brought me back.
It's still probably my most listened-to subgenre, but as of now I'm replaying a lot of other stuff. Other thing that "happened" was Mastodon releasing a new album around that same time - that one literally brought me back, maybe even more so than Maiden releasing Senjutsu.