That’s like saying email powers entire economies. It’s not WhatsApp that’s providing the value there, and if they press to hard to try and pull revenue from it, all that communication would flow into another channel.
WhatsApp is one of the buggiest UIs I use daily. Random things like images/messages stacking on top of each other, seeing the HD and low definition videos as two separate things in favorites, never being able to view the HD one, sometimes the messages never scrolling quite to the bottom, just amateur level stuff, I'm a bit impressed with how bad it is.