[wondringaloud]

I don't see how your anecdote differentiates between these two scenarios:

1. Human leaves, cat gets separation anxiety due to feeling less emotionally secure

2. Human leaves, cat gets separation anxiety because their primary source of food is missing

[wl]

I've seen cats bond with people who don't feed them.

Some cats are food motivated. Others are affection motivated. Some are both.

[jschwartzi]

I've had a cat eat my hair which is a grooming behavior they otherwise only do with other cats that they trust. If that isn't evidence of some kind of mutual relationship then I don't know what is.