Probably. WhatsApp famously supported over a billion users with <100 engineers: https://www.wired.com/2015/09/whatsapp-serves-900-million-us...

Prior to Facebook acquisition, WhatsApp was a fantastic engineering effort. I don't know if it's now sunk down to normal FB standards or if they're still good.

It might be enough to cover costs, but it's not enough to outweigh the amount Facebook can make by using everyone's data.