There are some interesting (and surprising) performance implications of using CSS animations that aren't widely known. Check out this video demonstration.
I'm going to take a deeper look into CSS Animations and how they fit (or don't fit) into a modern animator's workflow. You'll see exactly where some of the pain points are for a typical project and how they can bring your workflow to a grinding halt.
Why has GSAP become an industry standard for animation on the web? Here are a few of the practical, real-world reasons.