I can only speak for the market that I work in which is primarily Los Angeles but do shoot docs around the world. Apart from the cost reasons that I explained earlier, I truly believe the main reason we don’t see more cameras in this form factor is physical size. There is a whole generation of documentary operators that have never used a camera in that style.....many don’t use viewfinders....just onboard monitors...everyone wants small so the camera is more versatile. A camera like an FX9 can be made to be quite small for a gimbal and not much larger for a shoulder handheld configuration. That’s what the majority want. If there was a demand for larger form cameras there are plenty of manufacturers to make one. Sony make a very high quality 4k camera albeit a 2/3” sensor but it only really gets work on reality shows and news gathering. Personally I want a smaller camera setup to get it into tighter spaces and also so I don’t get as fatigued. I spent thirty years with EFP form factor cameras...I welcome the smaller rigs!