Earlier quoted context omitted.
Alternatives that exist openly in the US would not be suffered to exist in the PRC -- for instance, Signal.
Again, I see little difference between the PRC and USA in this regard. As an American, I couldn't care less about Chinese surveillance. But my own government has an active interest in monitoring my politics for thoughtcrime and influencing my thoughts and actions. Making a moral panic only about the foreign platform seems, itself, like propaganda.
This isn't mutually exclusive to being concerned about the US government actions in this space but the risks are completely different.