Yes, but why drag in 30k of additional library unnecessarily?
Yes use jQuery if it's really providing benefit, but if you're only using it for a few things, you may be better off just doing in in plain javascript, even if it's a bit longer.
Every library you add has an overhead cost on the end user as they have to fetch it and process it. It's easy to lose track of that when you're developing and testing against local webservers or on computers vs mobile, but there is strong value in keeping things small and with as few unnecessary dependencies as possible :)
Not sure if you read the page, but many of the examples are not "basic JavaScript syntax", the fadeIn approach is a function that attempts to replicate jQuery's, probably poorly.
No, jQuery did not invent the concept of fading in. It doesn't even have a unique implementation of it, it just does a few CSS changes that you can easily do without jQuery to get the exact same result.
This is as ridiculous as having a "addition" module in jQuery and saying that people who do addition in JavaScript are just reinventing jQuery.
Wrapping jQuery around something simple (like fading in) does not make it into jQuery. If anything this just demonstrates who incredibly unknowledgeable people are about where jQuery ends and JavaScript begins.
