I strongly disagree!
I have seen fantastic results with stereo cameras, colored lights, and self-calibration.
For most use cases, it's no problem if your robot will stop for a few seconds, rotate the camera axis around a bit, and then continue. But that appears to be good enough to calibrate the features for tracking things like a reflective and transparent glass jar.
As for the precision, I agree that 1cm at 10m distance doesn't work. But 1cm precision at 50cm distance is doable. And for a robot arm, you mainly need the precision when you're close to the object.
And yes, I am talking about what you probably meant with learned stereo matching. I would call it close to solved because we can by now do unsupervised training and achieve usable results. While I had trouble reproducing this specific paper, the general idea is valid:
https://github.com/google-research/google-research/tree/mast...
https://arxiv.org/abs/1904.04998
We are also seeing good results from using random YouTube videos to train AI vision.
But given that you are so sure that this is unsolved, I wonder if I should start a company to sell my depth estimate pipeline. Would you have any example image pairs that are causing problems, so that I can see visually what fails?