Do the paper timetables even exist anymore?
I never tried to "analyse large numbers of routes for business purposes" using those free printed guides, but I did use them sometimes when planning trips, real or imaginary.
Rather than "can I go to Paris and Brussels and back to Venice again in three flights" what I wanted to know was "what airlines fly between cities 1, 2, 3, etc. and what are all of departure and arrival times for the flights they have on those routes."
Today I might use that information when deciding what to price information I want to scrape.
I wonder if today there is a digital source of that information, free for public access. Probably not.