Yeah. I mean, you are interacting with a human being. It’s not that you’re rude, you’re cordial and casual.

It’s just that it’s not like a “thank you” thing. I’m more likely to thank a waiter just because they brought me a drink and put it in front of me, so it gives you more of a cue to say thanks specifically. Leaving a place seems to suggest a polite goodbye type of interaction.