I have several thoughts here.
First, the movie we got should be seen as a Harley Quinn movie rather than a Birds of Prey movie. It featured some of the characters that will later turn up in the Birds of Prey team, but it's fundamentally a Harley Quinn movie. And can Harley Quinn be R-rated? Sure.
Second, what was WB's goal here. Was it to maximise box office, or to make the best movie they could? Obviously the best is to get both, but if you only get to choose one? And the path to maximise box office at any price leads to
Suicide Squad.
So to me the primary question would be if the movie was made better due to its R-rating?
I think it was. This isn't
Wonder Woman, where Diana constantly chafes against the way she is gendered by the people around her. This isn't
Captain Marvel, with its exploration of gaslightning and its quiet determination to persist. This is a full-on unfettered feminist revenge fantasy.
Man proposes sex in exchange for Bruce the Hyena. Feed him to the hyena. Man makes a lewd remark. Break his leg. Or as film critic
Charlotte O'Sullivan put it: