Earlier quoted context omitted.
Right, and this model is itself monstrously inefficient and a result of 19th century (and earlier) modes of production persisting due to the presence of a guild and the absence any reform in the legal system. This is how furniture making and shipping used to work too, but then we invented factories and wage labor.
Any sort of consulting work is effectively a bespoke product - I don't see how you can get to the point where you can 'mass manufacture' professional services.
These things don't necessarily require professional services. They certainly don't require taking time off in the middle of the day to go to an oak-paneled office with potted plants and an anteroom. We could organize our society to give people justice without traditional law practices. We've chosen not to because the benefits accrue to a well-connected minority and the downsides accrue dripwise to the rest of us.
Note that LegalZoom and a few others are indeed trying to do this, but even they are forced to equivocate that they're not really lawyers. It's the legal equivalent of making tobacco companies put diseased lungs on their cigarette packaging, except it's not correcting for an externality, but imposing one. Why do I even need LegalZoom for a will? Shouldn't there be a government website where I can register my will for free? Should I need a lawyer and a judge to give me a no-fault divorce?