Well breadth of legal practice areas are what machines are good at, a machine that can analyze one law can analyze all of them and with constant quality. To give a concrete example, if some rather arcane part of insurance law may be relevant for a contract, a machine can then analyze the insurance law just as it did with contract law. By contrast a human lawyer has to ask for advice from a more specialized lawyer.

The human element is a quite good argument, at least without a major shift in perception of lawyers. However, I think that automation will realistically change what lawyers do, as well as the overall market for lawyers. One 'easy' area of law would be scanning employment contracts for standard clauses and you get some information at each paragraph what it means. Third page: first paragraph gets a green background and a note on the side says standard language, three more days off per year than standard. Second paragraph gets a yellow background and a note that says may get you into trouble if you use a company notebook for recreational programming. Third paragraph gets a red background and a text "Highly non standard, check with a lawyer." In this example, a lawyer still gets involved, he just does not have to check for the routine stuff and if history is any indication, this is what will happen. The routine stuff gets automated and the interesting cases are referred to the few remaining humans.