Send me a ship and I'll give you my (brutally) honest opinion on it
A lot of my modern Harlivy takes are covered in point 2 on this post; TLDR though is that modern Harlivy, despite being allowed to be more canon and visible, ended up being made very boring and one-note due to being the flagship of DC's LGBT+ representation and hence held to the absolutely miserable, flattening standard that is Good Representation. If they aren't being in-universe titillation for cishet men because Girl on Girl Is Hot And For The Male Gaze, actually, they're basically boiled down to a handful of sapphic Pinterest aesthetics of "chaotic girl liker" and "be gay do crimes" and "cutesy date scenarios", and they both kind of lose their original personalities as a result?
Like a lot of their most compelling content was when they were relegated to a more subtextual relationship because they still felt like them, but now it's just Cheerful Wacky Harley and Sarcastic Grouchy Ivy Rolling Her Eyes at antics and they're not allowed anything deeper than that, for fear of any kind of controversy. And in fairness, criticisms of sapphic ships and the insane standards of purity to which they are held are an absolute minefield due to the one-two punch of Sapphics Are Mean For Not (only) Dating Men stereotypes and misogyny wherein male villains can be as dastardly as they please and are loved for it whereas female villains have to get the anti-hero treatment or they're Problematique. I remember ages of awful takes about how Ivy is As Bad And Abusive To Harley As The Joker because of things like cartoon slapstick fighting with Harley/calling her dumb exactly one time for getting them caught by GCPD. And we both saw the hellscape that was Catradora discourse. People throw tantrums on the daily over children's cartoons like Owl House because a lesbian was a slightly rude middle schooler. People will not only give the pass but adore messy, toxic, complex mlm love stories like Interview With the Vampire and NBC's Hannibal, but anything in mainstream media depicting a sapphic relationship with more nuance or flaws than a Pride month Sears commercial is beyond what anyone can handle.
But the fallout of this is that Harlivy finally has the chance to be canon and it's, as I said, the corporate Pride version of itself. These are two highly intelligent, deeply flawed women in their thirties with complex histories, past relationships, and unresolved traumas, who are both ICONIC VILLAINS IN THE ROGUES' GALLERY, and modern stories don't seem to want to let them be anything beyond sex-crazed hormonal teenagers whose biggest issue is really basic communication (but not as a result of difficulties from their pasts, ever, so much as it is plot contrivances), whose connection to one another is flattened so much as to almost be little more beyond how cutesy they look posing together in lingerie that looks like their villain costumes. And that's because writers, critics, and audiences alike won't let them be anything more than that, and that's a damn shame.