Comment by observationist

It's about getting as much money from the platform for as long as possible, regardless of the externalized damage done along the way. Anything that negatively impacts the "number goes up" goal, year over year, gets suppressed, ignored, or redirected. They hire a sufficient number of people so as to diffuse responsibility and the sense of wrongdoing by any one person or group within the company, and different aspects of the overall abusive mechanics organically get compartmentalized, so that no one manager or employee or department ever recognizes the wrongs being done.

You end up with a few greedy asshats aware of the harms being done that just don't care, lots of money being made, and plausible deniability all around, with things never getting bad enough for an employee to feel like they have to take a stand or report wrongdoing.