Didi/Uber was more complicated than just data stuff.

At a high level, chinese tech culture is an insane no holds barred cage match with very little legal structure to protect IP or employees or anything and most companies who enter fail at participating in this.

Didi did a lot of corporate espionage and sabotage at uber china. They'd have "double agents" working for uber they'd pay to f stuff up. This type of thing is not practices in america because it is extremely illegal, but it was fine in China at not something that uber could do "back" to didi. There were people on the uber china fraud team paid by didi to tip off fraud networks on how to fraud. In the last year in china, they moved a ton of important work back to US offices because the china office was "compromised".