Corporate catering is a market that is mostly not serving “tech.” Businesses of all sorts use catering. Car dealerships have promotions with “free barbecue,” random offices have lunch meetings with catered food. Retail stores often cater food for employees during inventory. Holiday parties are huge business.
Thinking that corporate catering is “food for overfed tech workers” is a ridiculous simplification. Corporate catering is worth billions and it isn’t even a majority of “tech companies,” who buy those services.
Reading the case study in TFA, it really doesn't seem like they're talking about car dealerships offering barbecue for an afternoon. Their focus is on delivering meals to office workers, and from the language I don't think they're talking about the occasional lunch-and-learn. Especially when they talk about "restart rate" I read it as regular catered staff meals.
Thinking that corporate catering is “food for overfed tech workers” is a ridiculous simplification. Corporate catering is worth billions and it isn’t even a majority of “tech companies,” who buy those services.