As @protist@retrofed.com just mentioned, it varies greatly.

The lunch at my kids school today is:

• Crispy chicken sandwich
• Tater tots or French fries
• Assorted chilled fruits (from local farms, usually blueberries, strawberries, cranberries, peaches, and apples)
• Choice of veggies: pickles, cole slaw, or cucumber salad
• Milk (1%, fat free, fat free chocolate, soy, almond)

Each of those gets a swap option (not as much variety here given what it is) for allergies and preferences (such as vegan options).

It would be really hard to try and make me consider that worse than what I just looked at.

Edit: Full disclosure, our kids bring their lunch every day, on Fridays they can get an extra treat like cookies or something from there though). My wife makes bread fresh, we get our produce from the local farms too as well as growing a few things ourselves, etc.