Facebook, for example, likely has a fair amount of personal data about a lot of people who don't have meaningful internet access. Something as simple as their contact information being saved in the phone of someone who uses Facebook mobile is enough for the company to create a "shadow profile" for them. That kind of data collection doesn't benefit the data owner by providing a "free" service in exchange for their information and it occurs entirely without their knowledge or consent. This is exactly the kind of privacy violation GDPR seeks to curtail and I think the benefits can and do extend to the global masses more than most people realize.