We've had ~15 years of focus on the DOM with the progression of jQuery to Backbone to Vue, and many other libraries. At least what I've heard of the Figma approach almost sounds like the Adobe Flash/Flex runtime.
That might only make sense for applications with high levels of information density and snappy reactivity requirements like Figma or Google Docs or a web map -- not for content-focused websites. Still, it's interesting to wonder if our arguments would be more interesting these days if we were discussing those types of approaches, rather than just fighting about React vs. Svelte, or this JavaScript module loader vs. that one...