CSS Houdini is (I think) still A Thing, but I believe the browser devs have (rightly!) decided to concentrate on fixing more important issues first.

I believe the CSS Painting API[1] is the most advanced of the set? It has shipped in Chrome, behind a flag in Safari, and there's a polyfill[2] that (may/may not) work for unsupported browsers.

But the key issue with Houdini is that it requires JS to be enabled before it can do its magic ...

[1] - https://developer.mozilla.org/en-US/docs/Web/API/CSS_Paintin...

[2] - https://github.com/GoogleChromeLabs/css-paint-polyfill