I think a lot of these points have been made better elsewhere.

The extended discussion of hypothetical US interference just because of a tenuous chain of connection to the CIA is just typical US-badism. The US frequently funds tools which they think further geopolitical goals and this doesn't inherently mean its untrustworthy, just that their methodology of control is more resilient to uncensored speech; the best example of this is TOR, decentralized, anonymous, and created by Naval Research and DARPA. The author can't concede this point as it'd bring up they're unsubtly simping for a different colonial power, one who does require such censorship.

Signal's centralized nature has always been a major criticism (and it's reasonable), however as a trade off it's easy to on-board the tech illiterate. It's nontrivial to set up a Matrix server and I've seen the difficulty of migrating activist groups there. It's good as a long term goal, but one also has to recognize that a person struggling with housing has different concerns and will prefer to use whatever their friends and family do.