This is why you have to know your threat model. I understand and accept that much of what I consider "encrypted" in my daily internet use, from SSL to something like Signal even, is probably not secure from a determined state actor who is targeting my traffic. There is mathematics knowledge in the Cryptonomicon of the U.S. Intel agencies that has never been revealed and likely only shared maybe with the U.K. given the nature of the relationship there since WWII efforts to defeat encryption.
The resistance to end to end encryption by these entities means they likely can't decrypt en masse probably because of processing requirements, but if you are a target they can spend a little processor time on, assume they have some of these tricks buried in the algorithms to ensure they can reverse most commercially available implementations.
I assume also that other nation-states have similar if not equal capabilities, although they probably have less leverage to incorporate such backdoors into commercial products than the U.S. since the game was pretty much invented here.