The ultimate problem with Babs as Batgirl, compared to Cass or Steph, is that she lacks a convincing motivation beyond 'was Batgirl in the Silver Age'.

Her original origin was dressing up as Batman and stumbling across a crime. Not exactly compelling material, especially in a Noir driven franchise as Batman. I honestly couldn't tell you her modern origin, and that really says something, IMO.

What exactly is her compelling motivation? Because compared to Cass, Steph and most other characters, she's had it easy. No dead parents, a father who's relatively respected, comfortable middle class and apparently, she's had enough extracurriculars to be just as effective a crime fighter as the guy who poured millions into his study to be the best crime fighter in the world.

As internal logic evolves, Babs only falls farther behind, IMO.