What a bunch of technical snobs
This whole thread can be summarised as "I don't use what the plebs use because I'm elite and I know better".
Along with "why would anyone in their right use Instagram or other app that I don't?" or "I can't understand why other people want to communicate with people. Unlike me, because I hate them all".
Tech users are a tiny fraction of normal users. And nerds aren't exactly known for leading fashion trends. When you see this graph plateauing, you'll know people are listening to you.
Meanwhile, for those (apparently blissfully) unaware of Whatsapp's reach, here's some statistics : https://expandedramblings.com/index.php/whatsapp-statistics/