Unless you buy sourdough bread you will find the bread tastes sweet.
Milk also tastes different.
Along with margarine it is currently considered unhealthy. As a consequence there is not a great range of butter or margarines. What butter exists tastes totally different to the Australian brands. I don't disagree with your remarks on sandwiches, but this varies tremendously from region to region. Butter may be a dirty word in California, but I can assure you that it is quite common in the midwest.