> Every flatmate we've had have ended up scratching the shit out of our non-sticks (even after educating them on how to use it...).

The rule is simple: those pans must never even be looked at by something metallic during use or cleaning. Wood or plastic are fine. I use wooden tools. Fingernails are not OK too.

Of course flatmates use to be quite anarchic and careless especially young ones.

Flatmates can also do bad things to cast iron, e.g. dump them in the dishwasher and let them rust. Can't tell you how many times I've had to reseason a pan. After a point I just stopped trying to educate them and said, "you buy your own stuff and feel free to ruin it if that's how you want to treat your stuff".

What happens to wooden tools after they are used? In my experience they end up in the dishwasher where they get ruined.

I put wooden spoons in the dishwasher. They don't last as long as they might, but they cost €1.

I'll handwash more expensive wooden tools.

Try bamboo. Can be soaked, it's great.

I wash them with my hands. Dish soap and warm water.

I don’t understand why carbon steel isn’t more popular in the US.

Other than heat retention, it’s as good if not better than cast iron in every way, and it’s way lighter to boot.

Agreed. We (US) own a couple carbon steel pans of different sizes. Incredible cookware for <$100 total. Far and away cheaper than our Le Creuset cookware and in many respects just as good