One of our former prime ministers, Paul Keating, came out strongly against the submarine deal. IIRC two important dimensions are that Australia has shallow waters which are not a good fit for the chosen submarine technology and that tactically it makes limited sense for Australia to focus on weapons to be used on our largest trading partner.
https://www.theguardian.com/australia-news/2023/mar/15/paul-...
I am not an expert on any of the above.