Already had a grounded/gritty Joker. The Dark Knight

What can they do differently from Ledger's performance? That was as gritty and grounded as you're going to get without taking away the humor from the character. But also, I wish they'd start embracing the character more like the animated series's version with Mark Hamill. I know the DCEU, or whatever universe this will be part of, wants to be a little more darker and mature than the MCU, but that's DC's biggest mistake. Being darker and gritty doesn't make always make it mature. Honestly even the animated series version of the Joker was more mature than Jared Leto's Joker, but it didn't sacrifice any of the aspects of what makes the Joker who he really is. And Ledger's Joker is really as close as you're going to get with being a grounded and gritty version interpretation