Depends on how narrow a definition of 'social media'. I presume with messaging apps you have social circles and you share content whether your own or of others.

I do agree that 'social media' has been used to describe large scale public social media platforms specifically by the reporters/media.

Social network is any network in which people hang out and interact with each other. WhatsApp fits that definition.

Whatsapp is the best example of how it is social media specifically because the social graph and influences function the same way - although I’m not sure how you all are willing to define it but we can at least acknowledge the overlapping functions - the group chats Im in receive forwarded messages that can contain poor sources, Whatsapp is pretty unique in that it doesnt tell you who it was forwarded from or who created the message originally. I’m in large 256 person group chats, and ideas/news/controversies/coordination spreads like wildfire!

Telegram is much better since people dont see your phone number if you don't want (I dont use telegram for its optional encryption feature), the group chats can be way larger and the source of forwarded messages can be seen and accessed