they can literally just exist in their own worlds imo and then do a once in a generation multi universe threat crossover flick to cash out and then reboot for the next batch of actors.DC characters don't need to rely on the gimmick of a shared universe.
You talk as if Joker didn't make $1billion or that Chris Nolan's Batman movies didn't either. They didn't need a shared universe, were standalones and were critically acclaimed. This is what DC needs to go back to.
Marvel need the shared universe because their characters are not known so they needed a gimmick to bring people in.
It's easier for someone to buy into an Ant-Man when you know it's connected to Iron Man. Nobody cares for a Moon Knight if it wasn't part of the shared universe. That IS the point of it.
A Superman movie gains NOTHING from being connected to a Batman movie and vice versa. They are going to sell regardless.
And If you think Warner are going to focus on unknown DC characters like Marvel do with theirs outside of the odd 1 or maybe 2 like I don't know what to tell you.