Marvel has seen success at the box office, and DC has its shares of failures. But don't dismiss DC's efforts too quickly, as it's proving it can learn from its mistakes. After Justice League flopped, Aquaman performed much better, taking in 1.1 billion dollars at the box office. And the highly acclaimed Joker earned over a billion dollars as well. Not only that, but its return on investment (ROI) was 1,949 percent - the highest rate out of all of Marvel and DC's films. DC is quickly closing the gap and catching up to Marvel's box office success.
But even if that weren't the case, how good a movie is isn't wholly determined by its profits. For example, James Cameron's Avatar made even more money than Avengers: Endgame (until the latter released in theaters for a second time). Does that make Avatar a better movie than Endgame - or even a good movie at all? On the contrary, the consensus is that Avatar was quite forgettable, despite its enormous budget and revenue.