It is pure nonsense to call China's SSN and SSBN programs 'prestige' projects with limited combat potential. These are highly capable combat platforms that pose a significant tactical and strategic threat to any nations that may harbor hostile intent towards China.
It is amusing how some people buy into this USN submarine invincibility sales-pitch, since this is pretty much the exact some sales pitch presented for every branch and system the US makes and operates.
If the sales pitch were to believed, the USAF would have cleared the skies over Vietnam in days with minimal losses, the US army would have steamrolled the PVA in Korea and Mcaurther would have launched his presidency bid from the top of Tiananmen square after he 'liberated' China.
The reality is that while both the USAF and Army/Marines have had their mythical top trumps stats punctured by real world experience, the USN has never faced a serious adversary in combat since WWII, thus there is little to contradict the carefully crafted and diligently maintained image of near god-like powers and total superiority.
That in a way is a form of psychological warfare, and the like has been well documented and used since ancient times in works such as the Art of War.
If you make the enemy think they are facing impossible odds, that will damage their moral and influence their tactical choices etc, which all translates into real world advantages if war does break out, and might yield massive benefits if the psychological impact is so great as to convince a potential adversary to scale back or even cancel research and deployment of certain assets, like SSNs and SSBNs.
China's nuclear sub tech may not be on par, or even close to US standards yet, but as with all other areas, such as aviation, the distance is shrinking all the time. And so long as China maintains spending and work, they are catching up all the time, and there may be a time soon in the future when the difference is so small as to be practically irrelevant. Much like how the J20 is set to drastically cut the gap between the PLAAF and USAF when it enters service.
In the age of shrinking US defense budgets and steady increase in the PLA budget, do you honestly think the US would not use all the tools at its disposal to try and maintain their lead? These publish reports are clearly meant to be read by China's civilian leaders, and looks like a transparent attempt to try and convince them that Chinese SSN and SSBNs are worthless and just a waste of money. The aim is to try and sow doubt in the minds of China's leaders above just how good nuke subs are so that they might limit or even cut funding into nuke subs, thus helping the US to maintain its current edge in nuke subs without having to spend massive amounts on sub R&D themselves.
Such a move would probably be enough to convince US senators and congressmen, but China's leaders are overwhelmingly of an engineering background, and work in different ways, so I would be very surprised of such a move would do much to influence China's leaders.
The reason that Soviet subs where so noisy for much of the cold war was because of their lack of advanced precision tooling. Once the Japanese sold the Soviets such tools, the noise level of their subs dropped drastically without major design changes or new features.
The kind of precision tools that China has access to now is unconceivable to the US never mind Soviets during much of the cold war, and with China's experience with modern ultra quiet SSK designs, it is really hard to see how the likes of the 093 could have a noise level like first generation Victors from decades ago. And to have a projected noise level for a sub that almost certainly has never sailed before just looks very very odd unless the report's publishers have a massive agenda they wish to push.
