React is popular because it re-frames the meat and potatoes of frontend dev as a simple input -> output problem. VDOM merely helps make this approach performant

React is popular because it re-frames the meat and potatoes of frontend dev as a simple input -> output problem. VDOM merely helps make this approach performant at scale - it has little to do with why people actually use React. Abusing MutationObserver to get "easy" 2-way data binding is precisely the sort of antipattern that React & Friends would have discouraged.