Residents of the US are still free to use whatever mathematical algorithm they want to encrypt their comms. Transporting OTP's across physical borders is trivial, and not technically illegally if not mistaken. Strong encryption is open source as you've pointed out. There's no law against using those open source libraries, nor any discussion to try to censor/outlaw them, AFAIK.
Policing the airwaves and internet pipes hardly qualifies as some major abuse of human rights, particularly when the best that the Intercept/Snowden crowd can come up with regarding things like "Parallel Reconstruction" is "abuse" of "surveillance power" to catch, e.g., methamphetamine traffickers [1].
[1] https://theintercept.com/2018/01/09/dark-side-fbi-dea-illega...
edit: Downvote due to disagreement? This seems to be the mantra of HN in recent years.