I am from China and I always thought I am very good at math, because I can get good grades at national Olympiad level math competitions. After I came to America, I realized that I got good grades in China because I internalized the math concepts by doing large amounts of problem sets and it was actually a very slow learning process. In college mathematics courses, I realized that some of my American classmates can grasp new concepts and mental models ways faster than me, without doing much problem sets. We have just been learning math in very different ways.
As an iOS developer, I would say state of web development is not true for iOS. Sure it is slowly evolved to the current state but the framework much more thought out than their web counter part.
I think there is also a incentive problem. Internally, from what I know, the performance of a team is always driven much how much metric it can drive, how much incremental revenue it can generate, how much more engagement this feature will drive, etc. The number of contents taken down doesn't seem like a sexy metric, so I assume no team wants to take this unsexy task.
I feel that this is almost an Tautology, I can also say "Polygamy reduces major social problems of monogamist cultures" and it is also true because the two are exclusive to each other.