I don't understand this sentiment. If you are not a web developer, and in particular not a frontend web developer, then you probably aren't building html elements with these fancy effects. And if so, then why does it matter what advanced things CSS is capable of?
> Can't this be done with Javascript?
You can totally do this with javascript. You can plop in a canvas, and use webgl to program this effect on the GPU, like a real graphics programmer. You would have to recreate all accessibility features of the html button on your own. Is it going to be easier? I doubt it. But you certainly can.