Extremely political. Many viewpoints. Some legitimate French grievances.

In the end, while this is the most detailed breakdown I have seen, there are multiple references to financial difficulties with the deal.
This is an older article, closer to the event itself, and about as neutral/matter-of-fact as I have seen:

https://www.politico.eu/article/why-australia-wanted-out-of-its-french-sub-deal/

There are also the diplomatic aspects of Australia's entering into the AUKUS agreement (which is naturally a contentious subject.)