I am reminded of BGP (Border Gateway Protocol). Anyone who has even glanced at the RFC of BGP could write an essay of the horrible mess of compatibility, extensions, non-standard design of BGP. It also lack any security consideration. The problem is that it is the core infrastructure of the Internet.
Defining something as insecure with the implied statement that we should treat it as insecure is unhelpful advice in regard to critical infrastructure. People are going to use it, continue to use it for the unforeseeable future, and continue to treat it as secure. Imperfect security tools will be applied on top, imperfectly, but it will see continued used as long as it is the best tools we have in the circumstances. Email and BGP and a lot of other core infrastructure that is hopelessly insecure will continue to be used with the assumption that they can be made to be secure, until an actually replacement is made and people start to transition over (like how ipv6 is replacing ipv4 and we are going to deprecate ipv4 if you take a very long term view of it).
It would be great if we could replace the whole Internet with modern technology rather than relying on ancient systems like BGP and email.
I've occasionally though of starting a long term project that could eventually do that assuming that politicians screw up things the way it looks like they going to do over the next few decades.
The idea is that a group of interested people would develop these new system with no requirement whatsoever to have backward compatibility or interoperability with the current systems.
Of course these new systems would not get widespread adoption. They'd probably only be used by the developers and a few others who are willing to essentially have two completely different systems in parallel: the new stuff for communications among themselves and the current stuff for everything else. That's fine. It means no pressure to compromise to get something out faster.
Lack of adoption is not a problem. That's where politicians come in. What we are counting on is that those idiots are going to manage to cause or fail to prevent some apocalyptic event(s) that will sufficiently destroy the current systems that when the survivors get around to rebuilding the Internet and communication infrastructure they are starting from a clean slate.
However suggesting that we should change things to eliminate the risk is good. We could eliminate car accidents completely if everyone went over the automatic driven cars that communicated as a mesh network. The Swedish "zero vision" could be achieved, maybe even with todays technology, but it would be a massive undertaking.
Replacing BGP would be a similar massive undertaking. Just switching away from ipv4 to ipv6 has so far taken 20 years and we have no date in sight when we can start deprecating ipv4. From what I have heard/seen, a lot of people are somewhat reluctant to issue backward incompatible replacements of core infrastructure because they look at ipv6 and fear that kind of process. Even seen some pessimistic talks that argue that it is impossible and the only way to achieve changes in core infrastructure is with incremental changes that are fully backward compatible. I am not really of the view but I do understand their fear.
My advice to people is not to abandon email, even if I doubt much people would heed to the warning that email is unsafe for government, business, people and their family. People will risk it regardless. Thus I focus on what may help, imperfect as those may be. In the past that was PGP in the form of enigma mail plugin. Today I am keeping an eye on the new pretty Easy privacy which hopefully can outsource the security to a library that attempts optimistic encryption when ever possible.
Signal will not make people immune to death squads, nor will any other technology. It was not that long time ago that members of Anonymous went after the cartel and we got pictures of people tortured and killed. It only take one trusted person who know a dissidents real identity or family or friends or community for things to get very ugly very fast.
If the PGP team promised security against state organized death squads then that's their fault. Pretending that technology will protect you against that kind of threat can be a very costly mistake.