One reason to point to this is the Nigerian crypto population which showed in Nigeria position as number two in bitcoin market.
I really do not know the actual volumes of p2p trading in these countries. However, with the recent ban on cryptocurrency by Nigerian Central Bank, p2p trading was destined to increase. The same will happen for every country where cryptos will be legally banned. The beautiful part is that, you don't really need any website for such p2p trading. A telegram group, or a discord channel or even a small whatsapp group will suffice. I am sure India will see a similar practice when cryptocurrencies will be legally banned in India.
These countries are considered as 3rd world for genuine reasons!