I think in the case of Lightform, their core projection mapping algorithm is already public and has open source implementations. It's called "structured light". A quick search turned up this open source implementation: https://github.com/jhdewitt/sltk
I could be wrong but I think they built their product on research that was already open and public. I believe the technique predates the company.
Their "moat" was never the mapping algorithm itself; it was the suite of tools (hardware and software) that allowed users to easily map content without understanding the details of that algorithm.
I don't think their problem was that everyone was flocking to the open source tools. I think their problem is that the market for automatic projection mapping is extremely small.
I think in the case of Lightform, their core projection mapping algorithm is already public and has open source implementations. It's called "structured light". A quick search turned up this open source implementation: https://github.com/jhdewitt/sltk