While many people like to block Flash for content reasons, Apple's motivation is more about security and performance.

Or, more specifically, Adobe's lack of interest in addressing such issues in a timely manner; at least on OSX.

In my opinion a flash animation still outperforms a CSS-based animation in many cases. The problem with flash was never that it was inherently slow, but that people abused it to do slow things. On the security front though, you are absolutely right.

But it's within Apple's control to improve the performance/battery consumption of CSS animations. It's not within their control to fix Flash.

The performance side has nothing to do with animation performance and everything to do with the resources used to achieve it. Flash will murder a macbook's battery and generate an absurd amount of heat, doing nothing more than streaming h264.

That's so true, and as more and more ads go HTML you will see crappy devs animating the dom resulting in poor performance on iOS devices and damaging battery life.

So the cycle continues.

This is already happening and it's driving me nuts.

So many sites consume way to many cpu time with js.