What can you say, if anything, without going into detail?
The work I did absolutely had positive impact on the world.
People rush to criticize and write off working in the defense sector, but it can be a very rewarding place to work. There are absolutely problems in that sector - bad management and regulatory capture being primary among them. (Ultimately, those are why I left.)
It’s hard to judge accurately from the outside. That’s the nature of classified work: by definition, you can’t know what you’re getting yourself into until you’ve jumped with both feet.
Is that what they say?
And that isn't even the half of it.
People tend to forget that the US government will pay out the wazoo to achieve things that are one-time successes.
Consider things like Operation IVY BELLS, or Project Azorian.
Now consider that same mindset applied to a long term investment. The possibilities are pretty limitless.
The government has spent centuries doing spycraft and has a budget in the billions.
This is the tactic used when journalist Gary Webb started reporting on the USA involvement with selling crack to Americans so they could fund Contra insurgents in Nicaragua.
They did this so well that other news organizations turned on the journalist.
I could easily imagine the USA not wanting to patch holes so they have access to the systems and these experts know this.
Many examples of deliberate weakening are documented, especially with the "export approved" stuff that we sell to our allies.
This problem goes beyond just encryption, and also involves deliberate data leaking (with plausible deniability).
So yes, you don't need to imagine it at all -- the NSA works to create and maintain access to "everything everywhere."