>>296697886
There's some easy performance scaling to be had in just increasing the size/depth of the NNs beyond what would evaluate on a mobile processor, e.g. GPT-2 -> GPT-3. There have been hand-tracking and even full body tracking from RGB cameras for a few years in the research with good accuracy, but required seconds of a beefy GPU to evaluate every frame. Distilling these models to something that runs in realtime with similar accuracy has been more of an effort.

For a third-party or hobbyist, the biggest uphill battle is getting labeled training data. I don't think there's anything good out there.