A lot actually ^^

Instant messaging is incredibly fragmented, I use Twitter to chat with people I know from the industry, use Instagram to chat with friends, Facebook for family and marketplace stuff, WhatsApp to interact with almost every business.

(I work at Texts)

I assume a lot judging by how many there are and how popular each are and that people want to communicate with everyone. Most of us may have most of our friends on one but then few on others and then at work probably on others. Without mobile apps though assume will be dead on arrival until it is and they might run into road blocks there and of course the platforms I’m sure will find a way to simply block this if gains enough traction and then the app becomes mostly worthless again for most. So while I’d love this and looks like a beautiful Mac app I’m not hopeful unless EU forces everyone to jump on board but then issues with encryption and privacy.

I would happily have paid for Pidgin back in the day.

Currently, I use Signal, WhatsApp, iMessage, Google Voice (I'm an American living in the UK, I use Google Voice for my US-based phone number and texting), Facebook Messenger, and occasionally Discord. I'm probably forgetting something, too.

The answer to the first part is a lot, in the 100s of millions, the second part is anyone's guess.

But the main question is, how many Messaging Platforms would allow a "direct" competitor to push them into irrelevance?