I was similarly impacted by this article. I lived in Manila for four years, and I saw remnants of this in my household and others.
The Philippines is still feudal in many aspects, including how poor people have no choice but to hitch their welfare to the rich landholders by becoming domestic workers like yayas, drivers, etc. The head of household, usually the matriarch in the Philippines, demands utter loyalty and commitment from them, with long hours and demanding conditions. In turn, the become a second-class member of the family who receives some support in times of need. I've seen whole extended families put through school by one yaya's long term employer. A good friend of mine hired a nurse to care for his childhood nanny, who lives with them along with several other domestic workers.
While I lived in the Philippines, I employed yayas to help care for my children. One in particular we employed for several years and she became like family. It isn't slavery -- she had a contract, regular schedules, wages, etc. -- but it is still an incredibly demanding job. I cannot stress how difficult it must have been for her at time to be away from her own family. On the other hand, we provided her with wealth and stability she just couldn't find anywhere in Manila. It was an imperfect situation that is very hard to understand unless you've lived it or close to it.