I work with a group based in India. They have a completely different culture around messaging. Things I would consider worthy of an email comes as a message from them (i.e. doesn't need immediate attention/ escalation).

They are also very formal when initiating new messages, almost like they're following the same social standards as if they met you in the hallway (e g. Hi, how are you? Btw, I have this thing I need to talk to you about.). Mind you, this is all the time after exchanging dozens of messages a day.

I'm not saying there's anything wrong with it, just lends some credence to what Musk said.