It really just depends on your threat model.
Think it in this way: What is the most secure way to walk in the city? You’ll need a team of armed bodyguards and wear a full bulletproof vest. Do you REALLY need this level of security? Who are you protecting from? If the answer is a criminal organization or law enforcement, then yes, probably. But if the answer is a random thief, then you’ll probably need to just carry a gun, pepper spray, knife etc.
Same goes for privacy online and messenger in this case. Are you an activist or a drug dealer? Then you’ll probably need Tails + something like SimpleX via TOR. Otherwise, if you are just concerned of typical surveillance capitalism (and don’t want the government to scan your chats like it probably will in the EU after Chat Control), in my opinion, Signal is the best compromise of privacy, security and convenience.
does signal’s censorship circumvention work for them? It is also possible to use Molly (signal fork) which supports TOR via orbot. If they cannot sign up in the first place, you could use SimpleX chat with TOR also via orbot, but you should figure out a way to send them your link or QR code without the government knowing, or they might get in trouble.
Molly (signal fork): https://molly.im/
Use TOR in China: https://support.torproject.org/censorship/connecting-from-china/