The long-standing debate of DCU versus MCU is one that has spanned generations, ended friendships, caused more than one tussle physically and fueled virtual arguments, I might just be dramatic but what I do know is that it's a highly-contested topic and since my entire existence is controversial why not tackle this age-old topic.
I'm going to say right off the bat I may not have all the facts as a member of Gen-Z so feel free to call me out on Instagram or Twitter, my exposure to both universes are through the film and TV with no comic book experience whatsoever but I’ve seen almost every film and TV series ever created by both so I have a pretty good standing to judge this debate on.
Both brands have mastered the skill of creating highly marketable and viral content that's both entertaining, educative, and intriguing and they both do it very well. In my version of Marvel versus DC, it's separated into two categories: Movies and TV series. So while others can choose one right off the bat my answer is more intricate than that.
The first category is movies, although both create amazing high-quality sci-fi movies with fantastic human elements, Marvel has superior quality in telling concise stories (with the comparison being a TV series which are long drawn out stories) they provide you with enough information to get the story and have everything make sense while leaving out and intermingling just enough to have you come back for a sequel and watch other related projects they have coming out. A good example of this is the Avengers movies and how they correlate with individual superhero story franchises while also somewhat teasing the end of the series from the beginning. DC on the other hand haven't gotten the movie thing completely down, they have amazing stories no doubt but the turnaround always falls a little flat either not giving the satisfaction or return on investment that you require as a viewer or a little too much is left out of the story leaving you slightly perplexed. A good example is the Justice League movies, the 2021 version of Snyder's cut should have been what was initially released, it's four hours but extremely satisfying in comparison to the 2017 release in which some pieces didn't fit.
In the other category there's TV series, DC have better retention in terms of series. They have a good pace and just enough intrigue to keep you coming back for more even when you fall off a DC series, it's worth the hassle to get back on to where you stopped. On the other hand, Marvel has good series but low retention, the stories are great but they don't have that je ne sais quoi that gets you hooked on a series the way DC does.
For many, this would be the most unsatisfying piece of writing in existence but I'm only being factual from my perspective of things so like I said before you can come for me if you don't like it, I don't care. The truth is, in my opinion, they're both equal. There's no one far superior in quality because each possesses something the other lacks as for character selection and quality, we can all agree that the character quality of both is superior and there's no basis for comparison.
So overall Marvel has the movies segment beat while DC has the TV series game on lock. So in the battle of Marvel versus DC in my opinion it's a solid tie.