“IANAL” and all, My take is that legal work is, and has been, a high status domain of knowledge work requiring skill, effort and hard work to aquire. What cannot be solved with Excel&friends, may not be suited for such tools (or so they argue, to safeguard their knowledge).

A highly competitive market keep firms from collaborating on common [open source] goals and processes. Firms may have value systems far apart in their mission guiding their own work wich creates a social obstacle. A highly competitive (read: expensive) domain as it can be - professional signaling towards clients and competitor includes status and quality services; in which open source may be irrelevant at best, and dedicated person-to-person conduct of business is one of the best ways to deliver trust and quality. Maybe as a lawyer, you are better off using such de-facto standards as Clio.

I believe our most recent ML & AI have managed to breath some air into the historically tricky task of computationally work legalese in a practic way. A firm would probably keep a successful solution to themselves.

My hypotethical 5¢. /j