Did you also stop using all Facebook products (Instagram and WhatsApp)? Many of the people I know who are proud of quitting Facebook are happily snapping pictures daily for Instagram or chatting regularly on WhatsApp.
If you are implying (through the use of "proud of x, [but] happily doing y") that this is some sort of contradiction, I challenge that implication. WhatsApp and Insta are entirely different products by the same company, which scratch different itches. Not everyone changes their social media habits based on a perception of moral failing by the company that purveys those services -- that appears to be something rather unique to a subset of individuals. Some people just want to be happier.
Potentially viable alternatives (Telegram, Signal, etc) are emerging for Whatsapp compared to none for the other two.
Edit: for Android devices, Signal is just as easy to use as WhatsApp.