Whether it is "easy" to use depends on how much you know how to use it. Obviously, the more you know HOW to use it, the easier it is. The real question you probablly MEANT to ask is whether it is easy to learn.
The answer is no. It takes time master even it's most basic function, which is the Bezier, vector drawing tools. Learning WHAT they do is easy, but learning to do them quickly and expertly just takes a LOT of time and practice.
The other issue is that Illustrator is NOT designed to create animation. There are much better AND easier tools with which to do this, such as Adobe Flash and some others. This, too, uses vector drawing tools, PLUS the controls and features that actually animate your drawings and render them into whatever format you choose to play your animations in.