I wonder why browser developers are compliant with this. Everyone accepted that <marquee> or <blink> was horrible, but this knowledge does not stop them to add

I wonder why browser developers are compliant with this. Everyone accepted that <marquee> or <blink> was horrible, but this knowledge does not stop them to add support for animated GIFs, CSS animations, video autoplay, and if a user disables all of this and installs NoScript to block JS-based animations, there is always some new surprising way to annoy users, like SVG animations.