Dan Abramov has said several times that switching React's codebase to ESM won't result in any magic size drops from tree shaking, as there's really not any "unused" portions of the React codebase.
My understanding is that React's synthetic event system is a large portion of its size. Dan suggested that React 16's support for custom renderers would allow creating a "lite" equivalent to ReactDOM [0] if people wanted to, and at least one person has done so [1].
My understanding is that React's synthetic event system is a large portion of its size. Dan suggested that React 16's support for custom renderers would allow creating a "lite" equivalent to ReactDOM [0] if people wanted to, and at least one person has done so [1].
[0] https://twitter.com/dan_abramov/status/938937405524017152
[1] https://github.com/jquense/react-dom-lite/