Neither is a perfect analogy, but note that in your example the customer is actually depriving the restaurant of their possession of some goods without payment, i.e. it's theft. The example here is about services being rendered.

Are you saying that labor being deprived of their, uh, labor, is not comparable to businesses being deprived of their goods?

I'm saying that legally speaking (not morally speaking), being deprived of intangible things (aka services, think "verbs") is somewhat different from being deprived of tangible things (aka goods, think "nouns"). Neither entirely different (obviously), nor entirely identical (obviously). They're not treated the same way in general and I don't think you'd want to treat them identically for legal purposes.

Restaurants regularly resell goods in cases like this. I’ve had it happen when I was 10 minutes late.

Worst case they can give it to workers at the end of the shift.

I wish they did that more! I haven't seen it happen much personally but I'm glad you've seen it a lot. I know not long ago I went to a restaurant where I saw meals had been waiting for pickup for several hours... right before they were closing. Probably easier for small businesses than chains/franchises I'm guessing.