These are not synonyms. These terms have distinct meaning.
- Private means that information is for your eyes only, yours and people with whom you
communicate. Nobody else can peek into them. No advertizers, no big-tech, nobody...
- Secure means all the communication is encrypted with modern encryption methods and
- Safe means this is your system and access to the system is granted by yourself, no
abuse from strangers, no hate speech and no trolling.