It's always surprising to see people use FB given their reputation and how it's common to lose accounts. I feel the same about popularity of WhatsApp.
Instagram and WhatsApp are still very popular though. WhatsApp requiring a critical mass to make it endlessly compelling for users. Lots of the techy people i know tried to remove themselves from WhatsApp for signal but they've come back lately as its impractical due to poor adoption.
Would be interesting to know how their monetisation share between IG & FB is split in different regions. As much as I hate adverts in general i even find the IG ads useful from time to time; especially the hyperlocal targeting.