The important thing to remember here is that you don't have to use all of these newfangled features. As stated in the write up, these are primitives for library developers (e.g. apollo-graphql) to build on top of. The only real development that affects end-users in the past year or so is the migration to function components but even then, you can keep using class components (although you do have to rename some method names but even then, the React team provides automatic codemods for that).