Surprised no one else has chimed in with this yet - but what is your threat model? Are you conducting terrorist activities? Good luck. Are you wanting private messaging between you and your friends - it’s probably fine - definitely better than texting. I will temper this with just keep in mind anything you send to someone could be screenshot, their partner could see it etc. You need to figure out who your potential adversary is before deciding if a communication channel is “safe”. First ask yourself “safe from what?”.