Even if AI doesn't help with any aspect of the service itself there are a ton of efficiency gains to be had from "the rest" of the work, which will make service margins less ugly. Every business still neeeds some form of sales and/or marketing, support, and back office administration.
And for a lot of services there'll be creative ways to squeeze efficiencies from tech/AI. For example roofing businesses used to send a guy to your house to give you an evaluation + quote; increasingly, they now send drones (https://www.roofer.com/).
The claim that there's a lot of efficiency to gain from _tech_ isn't interesting. I'm guessing when the author talks about AI, they're not suggesting to build a fleet of drones.
And for a lot of services there'll be creative ways to squeeze efficiencies from tech/AI. For example roofing businesses used to send a guy to your house to give you an evaluation + quote; increasingly, they now send drones (https://www.roofer.com/).