Here's the fundamental difference between the two:
Even though they both put the same amount of money and resources into their movies.
DC's mentality is to make money as fast as possible, move the overarching plot at as quick of a pace as they can, so that they can get to Justice League, and eventually, Darkseid, as fast as they possibly can. They're trying to catch up to Marvel as opposed to taking their sweet time to flesh out their characters Aquaman, Flash, and Cyborg and give them their own time in the spotlight, so that when the eventual Justice League movie happens, the people watching the film actually cares about these characters and are invested in them like they hope they are. It's very hard to get invested in a character when the most I've seen of them across 4 movies is 5 minutes.
Meanwhile, with Marvel, they did 2 Iron Man movies, with the second one featuring Black Widow, Nick Fury, and S.H.I.E.L.D. in a more prominent role, we had a Thor movie that introduced Hawkeye as a solid supporting character, along with Hulk and Captain America's movies, so that when they finally got to The Avengers, it actually meant something. I honestly am not that hyped for Justice League later this year, I'm looking forward to it, and I'm gonna go see it, but I'm not jumping up and down my seat, super excited and hyped about the same way I am with Infinity War, where I'm on the edge of my seat waiting for the trailer!
Bottom Line: DC is trying to rush their Cinematic Universe out the door to make the most money NOW, instead of giving it the time and development that it needs and deserves. Which is why nobody cared about the Death of Superman in Dawn of Justice. That should be an extremely huge deal for anyone watching it, because it's THE DEATH OF SUPERMAN, but instead it's just "Oh, Superman died. That sucks, I guess." Whereas Marvel was/is taking their sweet ass time to give all of the characters they have plans for the spotlight they need, so that the eventual Marvel superheroes vs. Thanos clash will be a HUGE fucking deal.
Hardware Comparison Threads:
PlayStation 4/Xbox One/Nintendo Switch: 2019 vs. 2020