This is a bit of a fuck customers adjacent, since this didn't happen at my work, but as someone who also works in foodservice, I was annoyed as fuck about this: yesterday my friend and I got food at the popular Mexican-cuisine inspired "build your own burrito/burrito bowl/etc." place. We placed the order online for pickup. I went in at the time estimate it said it would be ready. I waiting 10 minutes more for my order to be done. It wasn't that big of a deal -- I can wait for food.
While I was waiting inside, however, at least three white women in their 30s were there, getting huffy that they'd been waiting for "so long", all complaining with each other, each approaching the cashier at some point to complain, and asking other people when their orders were supposed to be ready, myself included. When I told them I just kind of shrugged, because I literally do not care about having to wait, plus I have the social awareness to see that they're busy -- people kept coming in and ordering. There was a line, the entire time I was there, at the register. They were not only helping people coming in and ordering, but bringing out 5 bags every 10 minutes or so of online orders -- not just small bags either. Family sized orders. They were very obviously busy.
When they brought mine out, I asked the worker if they accepted tips, and ended up leaving them what I had in cash and telling them I appreciated their hard work. I wish I could've left more honestly, because if there were three Karen's while I was there, I can't imagine how many they dealt with that day alone. Honestly, fuck customers like them. If you haven't worked in foodservice you don't know shit.