Just to get this out of the way, 'things over other sites' is entirely subjective outside coded features. Why we recommend this site, why we love it or while we stay changes for every single person. This is just a brief and broad answer to tell you the most common/basic reasons. If you have different opinions or experiences, then that's fine! We'd be interested in knowing your problems to help improve the site! There's no right or wrong answer here.
1.) Unique community. Fast, interactive and responsive members answer your questions fast. If there's something that doesn't exist on the site - ask it and the information will then proceed to exist.
2.) Uncluttered, formulaic and neat. Everything is easy to get to, easy to find and easy to search for. And again if it doesn't exist, it soon will.
3.) Information is broken down and easy digestible. Both of the general information pages where everything is super simple and easy to follow to the Q&A where many people can give you explanations and interpretations to help you understand.
4.) The Q&A forum system is relatively unique and provides a precise catalogue (or Database, hence the name) of information - past and present. Ripe for the taking.
To answer your questions/statements:
Difficult questions may take some real time to answer because they require indepth knowledge of mechanics and formulas. These often take very long periods of time to test or knowledge of the game code, which not everyone has access too. There are a lot of us and we try hard, but we're only human and we each have our own real responsibilities.
To websites 'having it the same way', that's a little more subjective. In general our site is more broken down and easier to navigate and find information than others, but of course it might vary. And whether or not something is easy for you to understand depends on you. My point was that this site is definitely one of the easier to understand, and if you don't understand it, we can make it clearer for you personally. Most sites can't or won't do that.
As far as I'm aware, we're the only popular Q&A pokemon website. This specific structure and forum software are relatively unique.