Whatsapp is not Facebook, and it's not social media. It's a messaging application. Different thing. I quit Facebook -- I didn't exit every messaging platform. Yes, if you eschew every messaging platform, nobody can reach you. That's obviously correct.

However, nothing I use could be called a Facebook replacement, either. WhatsApp isn't a Facebook replacement.

Sorry, this is just how technology works. There is going to be a way that the vast majority of people want to communicate and if you don't want to use it, it's going to be a pain in the ass for you. This is always going to be the case, and nobody is under any obligation to accommodate you. If you didn't want to have a home phone in the 90s it would have been the same thing.

Of course but the argument was: "You're free to not be a user, but millions of other people want it.".

So the notion that you have complete freedom is somewhat false…

Who is talking about complete freedom? Nobody who lives in any human society will ever have that.

So? Just because there are reasons to compromise our freedoms doesn't mean we should stop asking which compromises are worth it and saying no to those that aren't.

It's not and it won't accepted. WhatsApp will be for third party clients.

No, this is how monopolies build their turf. Individually it is almost impossible to say no to that but as society we can simply outlaw these lock in tactics.

You might have heard of the phone network and email. Both provide you with choices as to which corporations you want to do business with without limiting what contacts you can talk to.