IRC. IRC has been around for the rise and fall of everything else on your list, and a dozen more that we've already forgotten. I have used IRC for my entire life and I see no reason to switch.
Don't get me wrong - I love IRC, and have used it as my primary social network for years. And after spending a full decade trying to switch people over to open protocols, I've found the hard way that the network effect trumps all.
I just don't see the average Whatsapp user ever switching to IRC.
The participants of this thread are not the average Whatsapp user - they're self-identified "hackers".