Cash grab. Has nothing to do with actual DC characters, even under context of this being outside of main comics chronology. And I am saying this while having read way more of Marvel comics, rather than DC. I mean, really, take Harley even and compare to any other popular adaptations, whether those where she was shows as "weak" or not.
She always was shown as chaotic, yes, and the one in this show is Harley is also somewhat chaotic, but... Like she is forcefully written into being that. I do not feel any drive behind that. And then I am comparing it to that other modern TV series (was it from Netflix?), where you could clearly see motivation behind any action, no matter how crazy it could have been.
Maybe this is a way to introduce the characters to Japanese audience who are unfamiliar with them? I mean, even Joker is shows almost as a gentleman. Much close to classic "insane villain" in anime, rather than an actual lunatic and anarchist from DC comics. That one also would not drive a car using a piano, since that would not even make sense.
I think they are trying to sell art-style here, but it is also hit-and-miss. Harley is cute, but that does not fit her character still. Katana's overall design is ok, but she looks too much like a child, and not a deadly assassin. King Shark seemed ok, and his "introduction" was the best thing in the first episode, to be honest. But everything else felt so shallow, second-hand, uninspiring, that it's a hard-drop for me.