They started out that way, as
@number9 points out below, both with the subs themselves and the first US-supplied combat system (that went through multiple company mergers/sales and design changes). A big part of the problem was the subs were much bigger than the Swedes had ever designed before and operated in a much different environment than the Baltic, from salinity to temperature.
The Aussies apparently worked the kinks out long ago and the
Collins are now excellent subs that the Aussies love. I worked with an Aussie sonar tech Warrant Officer (Master Chief) last year and he was more than happy to talk subs, waxing poetically about the
Collins in typical colorful Aussie style as well as mentioning not really trusting the 'fuckin bloody frogs' when I asked him about their replacements.
They weren't exploring the idea, they selected the French in 2016 to build 12 conventionally-powered versions of the Barracuda SSN's for $50 billion Australian, a cost had already risen to ~$80 billion by this year (presumably Aussie $). Coupled with serious delays and even some
embarrassing leaks the contract was in trouble enough that the Aussies refused to sign the next phase of the contract earlier this year.
It was got so bad that the
Australian Prime Minister met with the French President about it in June and told him that if the French didn't have their shit together by September the deal might get canx'd.
Quelle surprise, the contract was sunk.
While a few Aussies have advocated in the past for nuke-powered subs before now it wasn't being pursued by the government as they've historically been wary of nuclear power,
they banned it in 1983, though not as nuke adverse as their Kiwi neighbors. Chinese government actions and behavior have dramatically altered the calculus for the Aussies in just the past 2-3 years to the point where the political leadership is willing to acquire not only more 'strategic' nuclear-powered submarines but also an even closer alliance to the United States, and public sentiment seems to back them on both.
The latest 'Block' also happens to cost about 1/3rd more than the
Astute-class and might be a bit bigger than the Aussies want. The Aussies will also want considerable technology transfer and share in the construction and that might help the Brits more than it would us, given their smaller industrial base for building nuke subs.
After the
Astute-class is done building, only 2 more to go, they will likely have a pause of a few years before they build a new class of SSN/SSBN's while we are just going to keep cranking 'em out, both
Virginia's and now the
Columbia-class SSBN's too. That pause might also give the Brits more capacity to start building boats for the Aussies as they get up to speed building them on their own and helping the Brits to maintain a more robust expertise than they would otherwise with a significant pause. I would not be surprised if that is a big reason the Brits are part of the pact.
Lastly, I think it is pretty damn rich the French are getting their panties in a twist over the cancelled deal. After all the shady shit they've pulled with arms deals for decades they don't have much of a leg to stand on to start complaining about losing out on this one.