As various professions like Law were emerging, the Church was well established as a career of choice, easily overlapping power in the secular and spiritual worlds. A young priest from a well-heeled family could afford a good education and a professional role as a prince (or at least senior manager) of the church.
The average priest-in-the-street, however, had more of a portfolio career, picking up priesting gigs in the neighbourhood and mixing those with other consulting and “enforcing” jobs.
Long parallels this “hollowing out” of the front-line parish profession with today’s “ever more casual and commercialised” professions.
I think it’s simply another reminder that our perception of work as a solid, predictable, 9 to 5, 18 to 65, activity is a relatively modern (and fleeting) construct of the Industrial Revolution. Work wasn’t like that before, and it won’t be like that after.