I can’t vouch for the author at all, but this seems like a nice detailed, technical look at the difference between the two.
TL;DR the 212CD is very good at what in biology would be called “sit and wait predation”. It’s designed to sneak into an ocean floor crevice and hang out there, possibly for for weeks until something comes by, and then attack it. The Hanwha offering, on the other hand, is less superlatively stealthy and maneuverable, but is much more flexible, allowing missile launches and likely having a much longer range.
No one needs nukes
Tell that to Ukraine.
That would solve nothing because they would be condemned for using it.
The point of nukes is to not use them. Countries with nukes negotiate. Countries without nukes get preyed upon.
Your comment is ridiculous considering there is an active war of invasion in Ukraine at present, and they traded their nukes in exchange for a promise not to invade. In retrospect, the nukes would have been better.