You really don't know how to read do you?

But really, it’s more accurately a chain reaction. Fire isn’t a ‘thing’, it’s not a system of repetitively interacting parts.

Fire is not a thing, because it is not a system of reusable parts that interact with each other multiple times. It’s better described as a chemical chain reaction. Every molecule is used exactly once.

I never mentioned high school. I never took biology in high school. I took physics instead. I gave you my specific definition. You thought it sounded like something you remember from high school, and ignored what I actually said.

That which takes in nutrients, processes them to support itself, and expels waste products.

Fire doesn't actually support itself. Each flame is gone in an instant, unique to the molecule it came from.
But is creates the illusion of continuity, which can make life a useful analogy for it sometimes.

If you still don't understand. I don't know how better I can explain it for you. I've already given you too much credit. I'm done.