We've announced removal of IE support but we haven't actually removed the related code. We will likely do that in React 19 together with other breaking changes

We've announced removal of IE support but we haven't actually removed the related code. We will likely do that in React 19 together with other breaking changes to the React DOM bindings. I wouldn't expect this to dramatically cut the size. Overall, we tend to focus on changes that increase the performance of the application holistically (see https://twitter.com/reactjs/status/1508847169905864707 https://twitter.com/reactjs/status/1508847169905864707 and next several tweets) rather than focus solely on the bundle size of React itself (which is fixed and becomes a smaller % as the app grows). But we've definitely accumulated some cruft we'd like to drop sooner rather than later.