Yes. But, that doesn't mean implementing these things is any easier. Maybe if you're sliding an element in and out, the WebAnimations API would suffice. If you're wanting to do advanced animation, you will end up creating your own library. With anime.js, you have better control over your animations. You can pause, play, reverse, and seek animations, as well as control their speed. It provides a powerful timeline feature which allows you to chain animations and control their sequence, something that is not available in the Web Animations API. You can also do things like line drawing and morphing, as well as animate CSS properties, SVG, DOM attributes and JavaScript Objects.

You can do most things natively, if you have the time and luxury of reinventing the wheel.