We've since introduced a message-bus layer that makes it possible to do it all over the internet etc, but adds the associated serialization and transport latency.
I wrote this blog post on that topic a while back after having seen various approaches robotics companies take and their shortcomings: https://transitiverobotics.com/blog/streaming-video-from-rob...
I imagine most of this code being reinvented on a daily basis at countless companies around the world, what a waste of human resources.
Open source works great for shared code that isn't part of the "value added" by a company. So for a modern robotics company, it makes a lot more sense to use Linux for instance rather than rolling their own proprietary OS. And to use an open-source compiler for building the code. They're in the business of providing solutions using robotics, not selling operating systems and compilers, just like countless other companies build their products on top of these infrastructural tools, and sometimes contribute bug fixes and improvements back. But the code that actually makes the robot work (vision, motion planning, etc.) is what they spent most of their funding building, so giving it away makes no business sense.
Basically, you're complaining about all companies having trade secrets, and ultimately, you're complaining that competition exists instead of just having a single company having a monopoly over a whole market.