Well they were basically only ever really concerned about two things (immigration and muh sovereignty), they didn't give a shit about anything else, they'd even say it would be worth the UK going backwards for decades to get out of the EU.
Canada and UK act all haughty about being superior to the US but we have MAGA here and the UK has similar, and there is a reason they are called TERF island.
I read that linguistically, Australian English is closer to American than British versions. Having never yet been there but occasionally having a Violet Crumble when available, I can believe it.
It's a mix of both. For basic things like elevator vs lift, Aussies will generally understand both words and use them interchangeably.
Historically there was a lot of British influence, but these days I feel like it's definitely getting closer to US English. A lot of media (movies, TV shows, YouTube creators, etc) in Australia is American, and a lot of American slang enters the vernacular that way.