I see what Gunn is doing as the thing you're asking for.I think Marvel benefitted from allowing the audience to grow with the MCU. When it first started with Iron Man, it was manageable and accessible. Gunn’s rush into an interconnected multifilm universe seems like a missed opportunity for the DCU to do something similar.
The DCEU rushed into a Justice League movie.
In the next three years, we won't even see the 'holy trinity' together. Superman and Batman and the Green Lanterns are walled off from any team-ups (except maybe from their own family/circle of allies). Wonder Woman's reappearance is at least four years away.
I see the "team stories" such as Commandos and Authority and Waller/Peacemakers to be the type of movies that introduced The Guardians of the Galaxy.