Whatsapp had $10M revenue when it was acquired[1]. Lots of so called "chatgpt wrappers" has more revenue than that. While in hindsight Whatsapp acquisition at $19B seems no brainer, no concrete metric pointed to that compared to him investing $19B in AI now.
Dude Zuckerberg bought whatsapp because FB Messenger was losing market share... nothing to do with Whatsapps revenue! Rather Zuckerbergs fear of FB products being displaced.