Off the top of my head: * It's easier to write without pulling in dependencies. * Being simpler syntax means smaller page sizes. * In theory, CSS animations

Off the top of my head: * It's easier to write without pulling in dependencies. * Being simpler syntax means smaller page sizes. * In theory, CSS animations can be faster. * You don't have to worry about attaching listeners to dynamic content. * Styling with JS violates Separation of Concerns. * `prefers-reduced-motion` is only available in CSS, so JS has to run a CSS query anyway.