As stated, in my opinion, it's irresponsible to deploy unbreakable two-party encryption at a national/global level. IMO, authorities should have a way to decrypt the encryption used by the masses, when needed.
Further, it's clear that policy makers will typically push for such a mechanism. If such three-party systems are to be deployed, it would further your privacy cause to help to develop such a system, if your efforts to push back without compromise do not bear fruit.
Why not? People could say anything to each-other in private - shouldn't the authorities have a way of finding out what was said, when needed? How does the medium of communication change things?
Further, it's clear that policy makers will typically push for such a mechanism. If such three-party systems are to be deployed, it would further your privacy cause to help to develop such a system, if your efforts to push back without compromise do not bear fruit.