Are you serious? Marvel has always been far more guilty of this.
Dc has The Flash, so Marvel create Quicksilver.
Superman to Hyperion and The Sentry.
Batman fights evil with money and Alfred's help? Well, Ironman does it with money and Jarvis. Moon-Knight is a Batman parody.
Slade Wilson to Wade Wilson.
Doom Patrol ripped off by X-Men.
They liked Darkseid so much they ripped him off twice with Thanos and Apocalypse.
I suppose you think Hawkeye predates Green-Arrow?
And Ant-man totally isn't based on the Atom, right?
And don't get me started on the Black Cat/Catwoman debacle.
Peter Parker's classic protrayal has always had a lot in common with Clark Kent.
Bullseye's creators were certainly inspired by Deadshot.
The Nova corps concept is totally original.....not, rip off of the Green Lantern Corp.
DC starts a team called the Justice League...soon after Marvel creates the fantastic 4.
Bucky Barnes is a Robin ripoff.
And these are all off the top of my head; once I started typing, more and more unoriginal characters and concepts from Marvel that DC had already done came to mind, and here you are, saying that Dc take the ideas of others..