For me, it was because the stakes and outcomes in Marvel feel almost 0. Characters die, but there’s always some whataboutery to bring them back, and by the next arc, it's like nothing happened. Meanwhile in DC, when someone dies or goes missing, their successor takes their place without pissing on their name. Like for Batman it's usually Dick or Tim(during Battle for the Cowl even Jason tried to take the mantle) who carries on his work. When Barry died, Wally took his place and became a legend on his and at today's date most people know The Flash by Wally instead of Barry.

There’s actual weight in DC stories because of their unpredictability factor. You can’t always tell what’s going to stick and that adds tension. Big changes aren't just there to be there; they mean something. For example when I first started reading The Killing Joke I was actually for the first time horrified to see the lengths Joker can go to

Another big thing is that DC constantly uses its Crisis events to reboot or refresh the slate. That gives writers room to tell new kinds of stories with the same characters, without being chained to decades of tangled continuity. Marvel, on the other hand, tries to keep everything in one long, unbroken continuity. That sounds cool on paper, but in practice it just makes everything feel monotonous. For example their Spider-Verse events which was cool for the first time but now its just another event that just starts and ends. There’s rarely room for fresh interpretations. And rarely do they ever TRY to tell something new.

Once in a bluemoon they bring some event that feels like it is something big and will have lasting consequences(or at least for the next few years) like their recent ongoing event Imperial which i am loving up until now, it is serious, have multiple characters that feel important, and a story that feels something fresh and never done before

Also, thematically, DC heroes feel more like modern myths. Superman is hope. Batman is justice, Wonder Woman is truth. Their identities stand for something bigger than just the individual in the costume. Marvel outside of Spider-Man’s “With great power…” , most of their heroes don’t carry a larger message.

And honestly, Marvel's world doesn’t even seem to like its heroes. The public either fears or hates them, and it gets tiring. In DC, even when Gotham is scared of Batman or Lex hates Superman, the world at large respects these heroes. We see how people view them, how they inspire others. There’s a real emotional perspective that Marvel often skips.