Developers inevitably write slow, error filled code when dealing with Python and working with the type annotations can be a pain.
Happy there's something to replace PhysX for robotics, and I do really like MuJoCo's API, but really wish we could get some good C/C++ APIs.
Apart from the language, NVIDIA doesn't seem to be great when dealing with software. IsaacSim and IsaacLab have so many bugs, are incredibly slow, and hard to debug. We spend so many hours on my team findings bugs for IsaacSim, it's just a pain. On version 5.0 and still feels like beta software.
Also IsaacSim's relience on USD to hold the scene structure and update prims makes it so hard to program for. USD isn't really performant when trying to generate a large amount of scenes. And the USD interface stops working completly when simulation starts on IsaacLab. I hope Newton goes a different route, and has less of a reliacne on USD. IMO USD should just be used as an interchange format, rather than how you actually represent the scene and properties internally. I much prefer that approach, which Unreal Engine seems to support.
Lastly, my god the names in this field are terrible. USD (Googling becomes a pain sometimes), Newton (Already another engine), Warp (literally the name of the architecture and a way to write Python GPU kernels, wtf).