Depending on how you do rendering, vanilla JS can be extremely fast. For most web apps, the initial layout and rendering take the biggest portion of the render

Depending on how you do rendering, vanilla JS can be extremely fast. For most web apps, the initial layout and rendering take the biggest portion of the rendering budget. Subsequent changes are minimal and can be rendered very fast. If you can avoid re-rendering the whole page for every little change, the update can be fast. React's advantage is to track the changes for you. That doesn't mean you can't track the changes yourself. And if you structure your rendering and refreshing pipelines correctly, vanilla JS would do just fine if not better.