There are some people who think that the DCEU is already done. Some say that perhaps, this will not be able to recover especially since MCU is soaring high. Justice League was released in 2017 and even though people expected a huge turnout, it was a flop. This has made their movies a bit unanticipated by people.
Wonder Woman was supposed to be released in the year 2019 but it was moved to 2020 again. People are more excited about MCU movies right now. Only time will tell if they would be able to recover. As of now, they still have fans who are more than willing to spend on the movies that they release.
Of course DC will recover after the release of Infinity War, a huge hit by Marvel. The idea that only one of these companies can exist at a time is a very close minded point of view. The strengths of each individual company are very different and fans will continue to love and watch and appreciate each of them separately. Infinity War was the result of a multiple years long story line and build up to this release. It was always going to be a show stopper, and it does not have anything to do with the DC universe at all.
There was only one thing that the huge success of Marvel Studio's Infinity War shows DC and that is that fans still love the superhero and comic book adaptions and will still go out and watch them. It had been questioned whether or not people have grown tired of the superhero movies and perhaps would not be as excited about them but Infinity War proved that to be wrong.