More pressure means stricter requirements for all of those non-obvious steps like bending and soldering, and specialized hardware for things like joints and bearing.

Both of those mean specialized factories, supply chains, and labor. AKA higher prices unless it becomes the dominant option.

Also, in larger systems higher pressures is a safety concern.

None of that is a showstopper. But those are severe hindrances for a technology. A government can just fix every one of them, but then it would require government involvement.