Any business can be run in a shady manner if the human decided. One fully automated business I think could exist and might be useful is apartment/condo rental. I'd pay a business $100 for a proper report on the rentals available in a city that meet a criteria and are amalgamated from all the the various platforms. Doing it yourself (at least in Canada) means creating accounts on a bunch of platforms, and the process is very tedious.

Market making?