It's probably even better than that. If I'm going to spend $2400/yr on lunches (with after-tax money) and I'm in a 40% combined state/federal marginal tax brack

It's probably even better than that. If I'm going to spend $2400/yr on lunches (with after-tax money) and I'm in a 40% combined state/federal marginal tax bracket, that's consuming $4000 of gross pay annually. If my employer instead chooses to provide the meals, they are tax-free to me and 50% deductible to them, meaning the benefit that was consuming $4000 of expense to the company is now costing them perhaps $2000. (That's before assuming any efficiency other than tax treatment efficiency.)