It was a different world in the 80's. A lot was possible without worrying on lot of other things. Pakistan was training and sending jihadists not only across Afghan border but towards Kashmir as well. Something that's not possible today. Pakistan had full US support, it was receiving funds. US were only concerned on defeating & hurting the soviets. They weren't concerned on anything else. Plus Pakistan was not under the thumb of IMF, there was no FATF watching closely etc. ................. Just imagine, if Pakistan would not have become nuclear power in 80s. Would it be possible to become nuclear power in today's world. Not a chance!..... So its a different world today.
Secondly, building a submarine that will carry a SLBMs with sole intent of nuclear strike is NOT going to happen for Pakistan. I don't see this happening in our lifetimes even if Pakistan transforms into a great economy. There's simply no need for it. Pakistan is not Russia or China. I don't understand when people consider Pakistan to be some world power. We have to be realistic in our assessments. Pakistan hardly has enough frigates and attack submarines to defeat IN fleet which is immediate concern. Why would Pakistan put time, money & effort on a platform that will most likely never going to be used in a war at all. Do you really think that Pakistan, an islamic state whose nuclear weapons are point of concern already for the western world will be allowed to do so especially when you are under their control via IMF and other tools.
As far as nuclear triad is concerned, our primary concern is not Russia, China or United States. Our primary and sole concern is India only. The limited range babur SLCM can carry nuclear weapon so the triad is sort of complete already (as far as india is concerned). BTW, india / Pakistan can never destroy each other completely at first place having limited war heads and being neighbors. So, Pakistan really have no need for SSBN with nuke tipped SLBMs. we really are no russia or china or major world power. Pakistan needs to get the economy fixed and then do tons of other things which should be priority even in military sector before such endeavor.
Totally independent nations may require or desire such global reach with lethal weapons. Such powerful nations can do their decisions themselves. Such nations can make their own foreign policy. I mean what we are going to do with such stuff when our position currently is such that we think that whether this PM would be acceptable to xyz country or not, should we say this thing or it will annoy a foreign power, etc.. We have to lower our expectations with the state and work step by step.
Lastly, you have to be satisfied that Pakistan Navy is on right track. It will become a formidable fleet with the addition of these subs and new surface ships. Just look back few years ago, it was almost nothing, just had 3 agosta subs and 4 F22Ps rest was complete junk. Even the 4 F22Ps with no proper air-defense. So, you should be happy how things have turned for Pakistan navy. They are focusing on immediate concern that's creating formidable A2/AD in our area of interest. All resources, effort is on platforms that add value to conventional strike capabilities, which are 100% sure to be used in a war.