Where is the support structure?
The techniques and equipment being used are not the same as pouring concrete out of an old mixer. I do have one and it is and incredibly useful tool, but that is not we what we are discussing.
The major hurdle is not providing the “support structure” or foundation which is typically made out of concrete, or the trusses, beams, or joists which are likely still using the same old materials in most builds. The major problem is going to be building departments, permits, utility hookups, various nonsensical requirements and other government related expenses. This technique is not an answer to every problem and the expected savings are only around 30%.
It is humorous that you seem to want to pretend that advances are not being made that could be helpful in certain situations.
Un-reinforced concrete-oozed walls?
Pass on that deathtrap.