Somebody else already mentioned Brazil but I feel like in the rest of Latin America, alas, it's going strong. Lots of pages and groups still working with lots of engagement.
Here in Mexico everyone is on Facebook. But they don't use it in the classic way, posting vacation photos and family updates. Instead it's a way to find out the hours and location of a restaurant, what night your favorite band is playing, what barrio is having a fiesta this weekend, etc. Most businesses have a Facebook page but no web site.
SEAsia too. And not just for typical social; many businesses dont have websites, just a FB page. A lot of online shopping via messenger and paid in cash on delivery, because so many people dont have credit cards.
In many parts of SEAsia FB is synonymous with internet, because FB heavily subsidizes data plans.