Western governments have been ensuring that general public does not have access to encryption since clipper chip and likely before. Once computers got powerful enough and electronic communication got cheap enough they got worried and have been working to sabotage any true E2E ever since.
Which is why taking advice from government agency, let alone allowing them to set enforceable standards should be opposed, and to the degree advice from NIST/CISA/FBI/NSA etc should be followed it needs to be run thru the common sense test and smell tests, and independently evaluated BEFORE implementation. In most cases it is good advice. As long as the threat model isn't - keep your data away from a 5 eyes agency.
Realistically nobody controls the software stack, it does not matter how good your crypto is if you are auto updating and installing code that can send the data home after its already decrypted even if the keys do remain a secret in some secure enclave.
Realistically for most users the best place to keep the real keys to your personal the kingdom and your most private conversations, is probably a second mobile device from a reputable vendor that mostly remains at home and use something like iMessage or Signal. Reboot the device often only install the handful of applications you need, don't use it for browsing. That really should keep your stuff beyond the reach of most threat actors. Will dear old uncle Sam still be able to get into if the situation becomes serious enough they are willing to expose methods and practices, perhaps after some public theater where they pretend to need Apple/Samsung/Alphabet's help and/or that they have to really coerce that cooperation, certainly. However we probably really are into if you have not done anything wrong you have nothing to hide territory there...like if you murder 10s of innocent people in a night club or something f-u I hope society does rifle thru your stuff.