You have completely failed to even consider my basic premise and have gone off on a tangent. I did not say a submarine's main disadvantage is its lack of stealth or the time it can remain submerged. I said a submarine's main disadvantage is that it reveals it's position by attacking and it has a low speed. A navy the size of IN can respond by saturating the surrounding area with depth charges they don't even have to detect the sub on their radars. So we counter such saturation attacks by wielding nuclear tipped missiles which makes any large naval formations a moot point. I don't see how whatever you have written applies to my post.
I hope you had not taken my last reply as a rebuttal but only as a talking point, especially the initial sentences of your post, to jump in a discussion.
Yes, I presume that a submarine can get detected on firing its load of torpedoes but I think that will greatly depend upon the kind of torpedoes you have as well as the tactical strategy and choices submarine staff will make in doing so, duration of time and success the targets will have in detecting the threat and avoiding it. Presuming that a firing will always reveal a position of a submarine and will lead to its sinking is incorrect.
Also depth charging is an age old technology, even if some start using rockets or mortars to saturate a small amount of area and even that is not a recent invention. if you have ever seen Navy doing depth charging it is a bloody intensive task. And my understanding is that a depth charge needs to be a bit near to a sub to cause any damage.
You can study the case of hangoor, it was a sub with older tech, needed to snorkel a lot and daily, had older more louder and unguided torpedoes, was against two frigates specialised in anti-submarine warfare, one was sunk, one ran away. Later whole Indian fleet tried hunting it and depth charged it but failed.
Nuclear tipped missiles or torpedoes is whole different ball game, it is a nice to have capability but one option that you end up wishing never to use especially against an opponent armed with nuclear weaponry as well. There is no such thing as 'escalate to de-escalate', that is plain bullshit. Basically, any thing nuclear is an option of last resort.