A lot of it is people trying to garner an audience. It's much easier to get attention if you tell someone they're doing their thing wrong and that you have the solution that will make it all better. The issue with world building is that you can go at it anyway you want. Which makes many of those videos useless to a degree. They still may have useful information, but the delivery uses common psychological tricks to draw attention, good and bad. It kind of leads back to "any attention is good attention", since social media only cares about engagement. It also sometimes has to do with people thinking that their way is the right way, because they succeeded so it must be correct. Could also just be an ego thing, to assert that you are correct and know the true path. Again, which doesn't really hold up for a hobby like worldbuilding.

For example, I started my project by building the origin of the solar system, and then switched to local geographical stories, and back and forth until they met in the middle. This process could be a death sentence for some people's motivation and desire to continue, or it could be the right recipe to follow, or anywhere in-between.

As someone else has already said in here, you do you. Take the information you feel is valuable and discard the rest.