The original decision was influenced by politics and naturally produced a clusterf*ck. The new one will do the same, but for time being it puts Scotty from Marketing ahead on the national security/defence (as well as economic management) polls. The upcoming federal election will be fought by the coalition on the: "Would you really trust Labor and Albanese with the nation's defence, security and finances?"
A really good comparison to how bad Australia's submarine policies have been is vs the US. LA Class attack subs have been in service since the 1970s, with one from the 70s and a majority from the 1980s still in service. The cost per unit was around $950million each in 1990. Australia went for the Collins class in 1990 at a cost of around $800 mil per unit, and they are saying they are obsolete after only being in service since 1996, the last one joining the RAN in 2003. We were then going to buy a retrograde diesel submarine from the French that would have had the same issues and problems of the Collins class at a cost per unit of around $3 billion, which is roughly the same cost as the current VA class in the USN.
PS for those who don't know the major differences between a diesel and nuclear powered sub. The nuclear one only needs fueling every 30 years, can stay submerged indefinitely, only restricted by food and maintenance, can maintain its top speed under water indefinitely, including cruising between operational areas submerged. Vs the diesel with about 80 days cruising range at low speed (less than half) surfaced or snorkeling to conserve fuel, limited underwater cruising speed and time and generally smaller and poorer crew accommodation, all limiting its combat service time and effective ability.