Secure from who? The law? Not likely. Some dude in his basement in Russia who really wants to know where I’m meeting my friends after work or what time my dentist appointment is? Big deal.
Honestly, who is actually stupid enough to still be sending sensitive personal information by text? It doesn’t matter what app you use to send it; once it’s sent, it’s inherently unsecure because now someone else has it in their posession with nothing but their personal integrity protecting it.