You&#x27;ll have to explain why in details, not at a high level. In particular the fact that a replacement could perform &quot;tens or hundreds of times better&quot; is an extraordinary claim.<p>CSS has tons of problems, but almost every replacement for CSS that I&#x27;ve seen proposed would almost certainly have worse performance characteristics than CSS, optimally implemented, would. Most of them kill parallelism and kill opportunities for optimal GPU usage—they&#x27;re proposed cures that are worse than the disease. The problem is mostly that browsers don&#x27;t implement CSS as well as they could due to legacy, not that the technologies are fundamentally flawed (though this is not to say that they&#x27;re not improvable, far from it).<p>To create a better architecture, you first need to have an in-depth understanding of what the problems in CSS actually are. Otherwise, you&#x27;ll just trade one set of mistakes for another. (In particular, a CSS replacement that optimizes for Web developer productivity will <i>not</i> necessarily have acceptable performance characteristics—too often, people assume that &quot;easy to develop in&quot; implies &quot;runs fast&quot;, which in fact these concerns are often in direct opposition.)