The real problem here is that these services (twitter, fb, whatsapp, etc.) are designed for use by educated, urban people who know the basics of tech. And they are then marketed to uneducated people in remote areas to reach growth metric targets that Zuck and co can fling around at their next meeting.

In the west and in the urban areas of SE Asia, these problems do not occur because the users are educated enough to understand how this all works and are less likely to fall for all these fake news and child kidnapping videos.

Now, in remote villages, the people are not educated in technology. People who don't have access to electricity and TV suddenly find themselves using Social Media. These people don't have an idea that videos and images can be faked using Photoshop and such. So they take these at face value.

In real world communications, people have developed a system of verification and trust. When someone speaks about such things, you generally ask questions like the source for the information. Then you decide whether it is a source that you trust.

Whatsapp has no such system to find and verify the source of information. There is no trust model. The basic assumption is that the person in your trust zone is sending you this information.

Combine this with the fact that the videos hit the base instincts of humanity (safety, especially of your children) and you have a recipe for disaster.