Australian beef is cheaper than Canadian beef, in Canada, the ocean is not the obstacle.

I don’t know offhand what the price of beef is generally these days (I am a vegetarian).

Generally speaking, capital and commerce steer towards efficiency. Goods from Australia will always be “less efficient” than goods crossing between Canada and the USA and Mexico due to geography.

The only way to make up for that difference is if goods are dramatically cheaper to produce (i.e China) to make up for the geographical barriers.

While it may work for beef, it can’t work for everything. So, Canada is generally stuck with the USA until it can find ways to export/import efficiently from other countries, and some things, like produce, can never work.