I keep seeing that proposed as a theory, but are companies actually outsourcing this work to Nigeria or is that just an assumption someone made because they kno

I keep seeing that proposed as a theory, but are companies actually outsourcing this work to Nigeria or is that just an assumption someone made because they know delve is more commonly used there? A lot of these posts can't even decide which African country to blame it on. I've heard Kenya and Nigeria and just 'Africa' in general.