Idk. The 89 Batman Joker was, at least, idk, happy? Fun? Like he was very, very camp. The whole movie was high melodrama camp. It knew it was silly, it loved being silly, but it played everything seemingly straight. But it was silly. It understood batman is a silly concent. Gotham is a fairy tale city that's somehow both the 1930s and the 1980s. Jack Nicholson's goons are actual clowns in clown costumes. His evil plan is evil toothpaste that makes you laugh yourself to death.

Compare to Heath Ledger batman who is just a guy who shoots people and sets off bombs. No joker venom, no clowns, just a guy setting off bombs "because he wants to see the world burn". Suicide squad joker is just leto being a method edgelord freak, being mean and gross. Nothing whimsical or goofy. And then idk what the fuck Joaqiun Phoenix joker is trying to do.

Plus, I mostly grew up with Mark Hamill Batman the Animated Series Joker. He, again, was goofy. Gag weapons, clown henchmen, harley quinn in her harlequin costume hitting people with hammers. It was batman batman - batman was always portrayed as a straight man, it was very dark and noir, but it was supposed to be fun. The writers knew the subject matter was silly. Joker was still doing actual crimes, stealing stuff, not just sadistically murdering people so the writers could justify batdork's violence.

I guess that's it; fascism can't be goofy. Fascism can't withstand whimsy. Modern movie batman is neither goofy nor whimsical. It's not fun. It's grimy and mean, you're supposed to somehow accept the premise that grim violent fascist batman is the right response or something.

Contrast with Birds of Prey or the Glorious Empancipation of Harley Quinn. It's very violent, but it's goofy. We're in on the joke the whole time. Harley is a comedy character. Her violent actions fall within the context of the goofy whimsical batman world where every petty criminal has a gimmick and a costume. When she goes in to the police station to beat the paint out of dozens of people she has an M79 with grenades full of colorful smoke and glitter! It's fun, the writers know it's a goofy premise, and they invite the viewers to be in on the joke with them. The Suicide Squad runs the same way. It actively engages with the silliness of DC, it's violent and sometimes very dark, but it never forgets that this is silly comic book stuff and never asks the audience to forget either.