Many of us use Telegram.

Others use Signal.

Signal advantages: tptacek thinks the crypto is good.

Signal disadvantage: It wont work with limited permissions on your phone according to some people on HN.

Telegram advantage: somewhat more userfriendly. Larger userbase. Works even if you limit its permissions.

Telegram disadvantage: every cryptographer seems to think their crypto is bad. Uncertainty wrt their relations with Russian government. (I think they are enemies but some think they are very good friends or blackmailed into cooperation.)