It could also make things much worse, due to Jevon's paradox. The way rich societies throw away tons of food because it isn't scarce, or how modern software is slower than ever because hardware is too cheap. If half-baked AI's lower *some* of the costs of law practice, we might end up wasting more resources than ever before fighting against the proliferating volume of it.
See, the sword cuts both ways. Prosecutors' office would run more efficiently, would pursue much larger caseloads (lower priority ones) with fewer employees and less time. Civil lawsuits could become much cheaper to file; trolling could expand from niches (like patent law) to much broader, more socially-impactful forms of warfare. The financial risk/reward equation is what deters this, and lowering the costs means eliminating the deterrence. And imagine regulatory compliance costs, when regulators feel emboldened to design regimes so elaborate they themselves don't understand them, because they have AI assistants capable of parsing them.