Uk definitely isn't a "wearing shoes inside the house" country unless their house has floors so genuinely dirty that you're better off not collecting detritus

I'm really not sure about Australia. If you live up north you barely ever even wear shoes.if you live on a farm you better kick off those filthy gummies before you step in the house. If you're a tradie, you'd better kick off those filthy Blundstones before you walk in. If you live in the suburbs, it's a coin flip either way.

Shoes on the main floor are ok but not upstairs

in the tropics you'd be lucky to find someone wearing shoes outside

Most people in the states can barely reach their feet. They have a special bench in their house for putting their shoes on, but they have to make sure they do a proper warmup routine, chair yoga, before else they'll pull something. Putting their shoes on is like the most exercise they'll ever get in a day. Too stubborn to admit they need their own handicap parking permit after they stole the one they use from their aging mothers. They take an ultralight backpacking camp chair for the two story elevator ride at work. They can't be expected to take off their shoes until they have to take their once weekly shower.

France is a shoes off country. However during winter we have indoor slippers

Living in Ohio (midwest U.S) its not entirely a yes or no and more of a "it depends". Ive noticed older people assume shoes on but anyone under 40 will either ask or assume shoes off at the door. Theres also a layer of midwest nice to the whole exchange of not wanting to inconvenience the other person, so you get situations where a party will start with everyone wearing shoes, but end with everyone shoeless.

Where do slippers fall on this? I'm a shoes off person, but in the winter I've started wearing slippers inside.

Slippers don't count as shoes.

Shoes stay at the door and showers are taken at night!