I mean,
CSS animations are cool, but CSS3 compliance is annoyingly un-standard.
but, ignoring all the issues with browsers and their inability to be up-to-date with the latest W3C,
Is there some sort of performance advantage over jQuery animations?
Why are they being implemented?
As a general rule of thumb, whenever JavaScript can be avoided and the same result achieved, it should be avoided.
It’s always preferred to use the native browser abilities as it will usually be better performance-wise, plus it will generally look better.
Additional points: