I honestly hope Houdini never makes it into a final spec. The demo use cases are interesting, but the last thing we need is more complexity in web development.
Browsers today already act more like operating systems than document viewers. Houdini basically takes it a step further allowing every app to bring its own renderer. Linux leans heavily into this today and it makes mundane tasks like global theming a huge pain in the butt.
> the last thing we need is more complexity in web development.
Thats one way to think about it. Another is that Houdini lets the browser be more simple - because CSS (as it exists today) can be moved into a reusable library that can be shared between browsers. In theory, if all the browsers supported houdini, they wouldn't need to maintain their own CSS implementations.
As an internal implementation detail for sharing code across browsers, that sounds compelling enough. Web developers would never need to no about it though, as its just part of a browser's rendering flow that happens to be shared by browser vendors.
In reality though, I don't see browser vendors playing well to that level. Sharing specs is slow, sharing rendering code would be a nightmare.
Beyond that, I've usually seen Houdini demoed with developers focused features, effectively adding small bits of your own logic into CSS rendering. That pulls it out of the shared library and into userland.
Browsers today already act more like operating systems than document viewers. Houdini basically takes it a step further allowing every app to bring its own renderer. Linux leans heavily into this today and it makes mundane tasks like global theming a huge pain in the butt.