Why say Western, when they mean US english? US tech & culture (Hollywood, Netflix, etc.) has an habit of bulldozing over non-English Western culture too.
UK, Ireland, Australia, Canada also contribute a non-trivial part of "Western" (English) culture. I'm always surprised by how many Hollywood stars are actually Aussies.
Yes, because Australian and British actors often must fake US American accents perfectly to get roles in Hollywood. Margot Robbie, Tom Holland, etc.
Less than you'd think. Most Australians don't sound like Crocodile Dundee, and the educated/upper class Australian accent is quite neutral/unobvious to American ears.
The tell-tale sign of Australians is the "r" sound they add to the end of everything.
Can you give an example of an Australian actor who plays an American character in a Hollywood movie using their native accent?
Non-Western English speakers might be unaware of the difference between US English and general Western English, due to the dominance of US English in Western English.