Regarding the reasons 1 and 2, I find this to be an interesting phenomenon when it comes to philosophy. Hardly any beginners to philosophy ever start from reading works that are considered to be complicated. More often than not people go through something more or less simplistic and/or at least one book or multiple videos to get a short introduction of general concepts and get them simplified and broken down into "understandable" statements. However, reading an interpretation, a simplified one at that, will never hold the same value as reading the actual work.

What makes the need for those simplified explanations to grow then?

An often heard complaint is about the complex vocabulary philosophers use, which excludes them for an "elite" group of some sort. However, that exact complexity is used to make the point clearer (clear as possible to be more precise) - the complex words are used for a precise and specific concepts and replacing them with simpler, more vague ones will eventually mean misunderstanding the ideas proposed to a certain extent. In the end, it's the very same goal to be as clear and precise as possible that leads to many's confusion. I think it goes back to the question whether or not one wants and is willing to risk misunderstanding the idea in order to have it simplified and whether or not one would prefer spending a lot of time reading and studying in order to widen their vocabulary and have the clear image of the proposed idea.