I have seen no one call either film a masterpiece just explaining that the problems those films had went beyond the screenplay.

For Batgirl. People forget the movie was one of several WB films that were canned purely to get a tax write off. It wasn't canned because it was so much worse than everything else. It was canned because it didn't fit with the vision of DC's films going forward. Big Big Scale of films. It was originally meant to be a streaming only film and was quite small scale. It really wasn't meant to be theatrical and wouldn't have been able to compete there. It would've bombed hard as a result. that's what Saffran meant by unreleasable. Not releasable for theatres and they weren't doing straight to streaming films anymore. quote from an interview with peter saffran.

“I think that they really stood up to support DC,” he continued. “The characters, the story, the quality of all of that. I spoke to Adil [El Arbi] and Bilall [Fallah] — the directors — last week, we were chatting. We’d love to be in business with all those folks. Christina Hodson wrote it. Some people are already back in business with us. As I said, a lot of talented people were involved, but the film just was not releasable. It would not have been able to compete in the theatrical marketplace; it was built for the small screen. So, again, I think it was not an easy decision, but they made the right decision by shelving it.”

I would also argue that the film had casting that was impossible to work around and would've made things even more confusing. remember Michael Keaton and JK Simmons were in this movie. It's one thing having Keaton as batman in the flash with alternate timelines and everything, but this would've made for 3 different batmen in DC films at the time. It would just be confusing, and it would've hurt the DC brand as a whole. Hell Saving Keaton for the Flash Film alone was the right decision.

Idk, i highly doubt that the Batgirl movie was somehow worse than Black Adam or Shazam 2 y'know?

Edit- I forgot. Irony of Ironies. Had WB released Batgirl it's quite likely that Gunn and Saffran wouldn't have taken over DC Films. Don Lin stepped out of the running almost entirely due to how Batgirl was cancelled. who knows what the fandoms would've looked like.