Houdini is actually one of my greatest CSS fears.
I'm afraid that, even if this allows you to seamlessly roll out a new type of layout rule, all this will create, ultimately, is more fragmentation in the ecosystem.
CSS, like JS, is already bloated and messy, struggling to be all things to all people. Now CSS won't even be declarative in nature anymore - it'll depend on JS, and the two will fuse into a giant, hairy ball of mud.
With Web Components fusing HTML with JS, what used to be declarative, semantic markup is now unreadable gibberish - this will do the same for CSS.
The web used to be a homogenous, human-readable medium. Now every webpage will use it's own version of HTML and CSS, and no two sites will look the same.
I used to be optimistic about the web - but now, there are definitely times when I think HTML, CSS and JS are all f_cked beyond repair, and maybe we just need to start over with something much simpler that actually does what we need.
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