Probably a little bit of both. Anecdotally, the fires and smoke columns are probably bigger than you realize. This is a pic from some time ago of a 10,000m tall smoke column from a fire barely 24 hours old and less than 100kms away.

We had the opposite happen at my work a little while ago lol. New person came in and saw that I carry a 1.9l water bottle everywhere with me and they started laughing asking why when there’s water and cups in the kitchen. Cue a week of various coworkers having to prove to this person that basically everyone in the office has a water bottle of their own that they regularly use at work. Still didn’t understand at the end and they also didn’t last long, oh well.

My entirely unqualified thought is that it gives the food stain particles something to bind to that isn’t the plastic of the container

Growing up in Canada, McDonald’s was provided to kids in hospital through the Ronald McDonald House Charities! I have fond memories of getting bloodwork done and being treated to McDonald’s because my parents never took us there…