How am I supposed to message people when the only messaging app they use is whatsapp and facebook messenger (which I don't use)?

I guess the only easy alternative is to use SMS and email since everyone use it. But it is not safe.

I am always open to alternatives like Signal, Element,etc. But no one use them. I am not going to force people to use a messaging app.

Thanks. May I ask what is so cool about the instance that I am on? ;)

Whatsapp. Everyone in India uses it. Its like the imessage situation in the US. So widespread.

Schools, college, friend groups, family groups all are on whatsapp.