Already has Lawful Access
Barr *already has* Lawful Access. There is an already existing process which, on reasonable and probable cause, can be used to obtain the clear-text of encrypted communications from either of the end-points of that communication. The problem is not that Barr and his cronies do not have access, the problem is that they do not have reasonable and probable cause to obtain a search warrant to obtain the clear-text from where it exists -- the endpoints.
Barr and his cronies want to be able to bypass due process in order to engage in massive fishing expeditions by obtaining the clear-text from intermediaries using the old "wink and nudge" method. Those intermediaries have finally figured out that they can bypass the whole issue -- and the expense and liability -- by simply not having access to the clear-text of the communication.
This really has nothing whatsoever to do with encryption or "going dark" at all. It has to do with being able to bypass due process because Barr and cronies are unable to meet the requirements to obtain the process that is already available.